bluuebunny/crossref_metadata_2025_split huggingface dataset:
Safety of instrumentation in patients with spinal infection
Authors: Rayes Mahmoud , Colen Chaim B. , Bahgat Diaa A. , Higashida Tetsuhiro , Guthikonda Murali , Rengachary Setti , Eltahawy Hazem A. 
Published: June 2010

ObjectTreatment of spine infection remains a challenge for spine surgeons, with the most effective method still being a matter of debate. Most surgeons agree that in early stages of infection, antibiotic treatment should be pursued; under certain circumstances, however, surgery is recommended. The goals of surgery include radical debridement of the infective focus. In some cases, when surgery causes mechanical spinal instability, the question arises whether the risk of recurrent infection outweighs the benefits of spinal instrumentation and stabilization. The authors report their series of cases in which instrumentation was placed in actively infected sites and review the relevant literature.MethodsThe authors performed a retrospective analysis of all cases of spinal infection that were surgically treated with debridement and placement of instrumentation at their institution between 2000 and 2006. Patient presentation, risk factor, infective organism, surgical indication, level of involvement, type of procedure, and ultimate outcome were reviewed. Improved outcome was based on improvement of initial American Spinal Injury Association Impairment Score.ResultsForty-seven patients (32 men, 15 women) were treated with instrumented surgery for spinal infection. Their average age at presentation was 54 years (range 37–78 years). Indications for placement of instrumentation included instability, pain after failure of conservative therapy, or both. Patients underwent surgery within an average of 12 days (range 1 day to 5 months) after their presentation to the authors' institution. The average length of hospital stay was 25 days (range 9–78 days). Follow-up averaged 22 months (range 1–80 months). Eight patients died; causes of death included sepsis (4 patients), cardiac arrest (2), and malignancy (2). Only 3 patients were lost to follow-up. Using American Spinal Injury Association scoring as the criterion, the patients' conditions improved in 34 cases and remained the same in 5. Complications included hematoma (2 cases), the need for hardware revision (1), and recurrent infection (2). Hardware replacement was required in 1 of the 2 patients with recurrent infection.ConclusionsInstrumentation of the spine is safe and has an important role in stabilization of the infected spine. Despite the presence of active infection, we believe that instrumentation after radical debridement will not increase the risk of recurrent infection. In fact, greater benefit can be achieved through spinal stabilization, which can even promote accelerated healing.
Hirayama disease
Authors: Lin Muh-Shi , Kung Woon-Man , Chiu Wen-Ta , Lyu Rong-Kuo , Chen Chi-Jen , Chen Tzu-Yung 
Published: June 2010

Object
Controversy exists over the choice of surgical candidates and prognosis of Hirayama disease. The purpose of this study was to examine the outcomes of patients with cervical flexion myelopathy who received surgical treatment.

Methods
A retrospective study was conducted. From May 2002 through December 2006, 6 young patients with cervical flexion myelopathy were seen in the Department of Neurosurgery at Chang Gung Memorial Hospital. The neurological and radiological findings in all 6 patients met the criteria for Hirayama disease. All patients had evidence of a tight dural canal or forward migration of the posterior wall of the dural canal in dynamic MR imaging studies. Five patients were treated with surgical decompressive procedures (4 anterior and 1 posterior) and 1 patient received conservative treatment. Duration of follow-up ranged from 13 months to 4 years.

Results
Motor function improved in 3 of 5 surgically treated patients and sensory function improved in 2. Neurological symptoms were unchanged in the conservatively treated patient. During follow-up MR imaging in the surgical group, anterior effacement during neck flexion was noted in 1 patient treated with a posterior approach.

Conclusions
Hirayama disease is so rare that it is easily misdiagnosed. Diagnosis is achieved via clinical presentation, neurophysiological examination, and neuroradiological imaging studies (dynamic MR imaging). The anterior decompressive approach may be better for patients showing anterior effacement and severe cervical kyphosis during neck flexion in MR imaging.
A radiographic computed tomography–based study to determine the ideal entry point, trajectory, and length for safe fixation using C-2 pars interarticularis screws
Authors: Hoh Daniel J. , Liu Charles Y. , Wang Michael Y. 
Published: June 2010

ObjectEffective methods for fixation of the axis include C1–2 transarticular and C-2 pedicle screw placement. Both techniques pose a risk of vertebral artery (VA) injury in patients with narrow pedicles or an enlarged, high-riding VA. Pars screws at C-2 avoid the pedicle, but can cause VA injury with excessively long screws. Therefore, the authors evaluated various entry points and trajectories to determine ideal pars screw lengths that avoid breaching the transverse foramen.MethodsBoth pars were studied on 50 CT scans (100 total). Various pars lengths were assessed using 2 entry points and 3 trajectories (6 measurements). Entry point A was the superior one-fourth of the lateral mass. Entry point B was 3-mm rostral to the inferior aspect of the lateral mass. Using entry points A and B, Trajectory 1 was the minimum distance to the transverse foramen; Trajectory 2 was the maximum distance to the transverse foramen; and Trajectory 3 was the steepest angle to the pars/C-2 superior facet junction without transverse foramen breach.ResultsThe mean patient age was 46 ± 17 years, and 84% of the CT scans reviewed were obtained in men. There was no significant difference in right or left measurements. Entry point B demonstrated greater pars lengths for each trajectory compared with entry point A (p < 0.0001). For both entry points, Trajectory 3 provided the greatest pars length. Using Trajectory 3 with entry point B, 84, 95, and 99% had a pars length that measured ≥ 18, 16, and 14 mm, respectively. Using Trajectory 3 with Entry point A, only 41, 64, and 87% had a pars length that measured ≥ 18, 16, and 14 mm, respectively.ConclusionsUsing an entry point 3-mm rostral to the inferior edge of the lateral mass and a trajectory directed toward the superior facet/pars junction, 99% of partes interarticularis in this study would tolerate a 14-mm screw without breach of the transverse foramen.
Surgical treatment of spinal intradural arachnoid cysts using endoscopy
Authors: Endo Toshiki , Takahashi Toshiyuki , Jokura Hidefumi , Tominaga Teiji 
Published: June 2010

Object
Spinal intradural arachnoid cysts are a rare cause of spinal cord compression. Since 2000, the authors have treated patients using 2- or 3-level hemilaminectomy or laminectomy followed by partial cyst wall resection as well as endoscopic inspection and fenestration of the cyst wall. They evaluated the usefulness and reliability of endoscopic treatment for this clinical entity based on long-term follow-up results.

Methods
Between 1997 and 2003, 11 patients (3 males and 8 females) with spinal intradural arachnoid cysts were treated, and the authors conducted a retrospective review of these cases. Before 2000, 5 patients were surgically treated without the use of endoscopic techniques. During that time, more than 4 levels of hemilaminectomy were performed to expose and remove cyst walls that extended longitudinally over the spinal axis. Beginning in 2000, endoscopy was used in all 6 cases. Up to 3 levels of hemilaminectomy or 2 levels of laminectomy were performed, and the cyst wall was resected through the bone window. An endoscope was inserted into the cyst cavity and moved in the cranial and caudal direction to fenestrate the cyst wall, resulting in communication of the cyst cavity with the subarachnoid space.

Results
Postoperatively, the neurological symptoms of all patients improved. During long-term follow-up (mean 114.8 months), none of the patients treated with or without endoscopy experienced recurrent cyst formation.

Conclusions
Endoscopic techniques allow neurosurgeons to treat spinal intradural arachnoid cysts less invasively than with standard surgical approaches. Although the number of cases reviewed in this report is small, the data suggest that the use of endoscopy can be an important option in the surgical treatment of spinal arachnoid cysts.
Facet joint opening in lumbar degenerative diseases indicating segmental instability
Authors: Hasegawa Kazuhiro , Kitahara Ko , Shimoda Haruka , Hara Toshiaki 
Published: June 2010

ObjectThe objective of this study was, using a novel intraoperative measurement (IOM) system, to test the hypothesis that an increased facet joint volume is evidence of spinal instability.MethodsIn 29 patients (male/female ratio 13:16; mean age 67.5 years, range 43–80 years)—17 with degenerative spondylolisthesis (DS) of the lumbar spine (Group DS) and 12 with canal stenosis (CS) of the lumbar spine (Group CS)—DICOM (Digital Imaging and Communications in Medicine) data derived from CT scans were transferred to a workstation. A 3D model of facet joint spaces was reconstructed and the average volume of the bilateral facets was calculated. Segmental properties—stiffness, absorption energy (AE), and neutral zone (NZ)—were measured using an IOM system, and values were compared between groups. Linear regression analyses were performed among biomechanical parameters and average volumes.ResultsStiffness and AE did not differ significantly between groups. The NZ was significantly greater in Group DS than in Group CS (p < 0.05) and significantly positively correlated with the average volume (R2= 0.141, p < 0.05). Stiffness tended to negatively correlate with average volume. Absorption energy did not correlate with average volume.ConclusionsBiomechanical analyses using the IOM system verified that an increased facet joint volume is evidence of spinal instability, represented by NZ, in the degenerative lumbar spine.
Craniovertebral instability due to degenerative osteoarthritis of the atlantoaxial joints: analysis of the management of 108 cases
Authors: Goel Atul , Shah Abhidha , Gupta Sanjay Rajan 
Published: June 2010

ObjectThe authors retrospectively analyzed a series of 108 patients in whom was diagnosed atlantoaxial instability due to degenerative osteoarthritis of the atlantoaxial joints. The management issues in such cases are discussed.MethodsOne hundred eight patients with osteoarthritis of the atlantoaxial joints and resultant craniovertebral instability—diagnosed on the basis of presenting clinical features, radiological imaging, and direct observation of the joint status during surgery—were retrospectively analyzed. Between 1990 and 2008, these patients were treated with a C1–2 lateral mass plate and screw method of atlantoaxial fixation and joint distraction using bone graft with or without the assistance of metal spacers.ResultsPatient ages ranged from 48 to 84 years (average 63 years). There was a history of mild to moderate head and/or neck trauma 2 months to 11 years prior to diagnosis in 40% of the cases. All patients had symptoms of neck pain, and 82% of the patients had progressive myelopathy. A reduction in the height of the atlantoaxial lateral mass complex (100%), mobile atlantoaxial dislocation (100%), basilar invagination (68%), and periodontoid degenerative tissue mass (90%) were the more frequently encountered radiological features. Two patients died in the immediate postoperative period. At an average follow-up of 64 months, all surviving patients remarkably improved to varying degrees in their neurological condition.ConclusionsAtlantoaxial joint arthritis frequently leads to craniovertebral instability and cord compression. Treatment by joint distraction and lateral mass fixation can be an optimum form of treatment.
The transpedicular approach compared with the anterior approach: an analysis of 80 thoracolumbar corpectomies
Authors: Lu Daniel C. , Lau Darryl , Lee Jasmine G. , Chou Dean 
Published: June 2010

Object
Whereas standard anterior approaches for thoracolumbar corpectomies have commonly been used, the transpedicular technique is increasingly used to perform corpectomies from a posterior approach. The authors conducted a study to analyze whether there was a difference in outcomes by comparing transpedicular corpectomies to standard anterior thoracolumbar corpectomies.

Methods
The senior author performed thoracolumbar corpectomies in 80 patients between 2004 and 2008. The authors reviewed medical records and follow-up data, consisting of clinic visits, radiographs, or telephone interviews. Neurological outcome, complications, operative times, revision surgery rates, and estimated blood loss (EBL) were evaluated.

Results
Thirty-four patients underwent transpedicular corpectomies, and 46 patients underwent anterior thoracolumbar approaches. Single-level transpedicular corpectomies appear to be comparable to anterior-only corpectomies in terms of EBL, operative time, and complication rates. There was a higher complication rate, increased EBL, and longer operative time with anterior-posterior corpectomies compared with transpedicular corpectomies. Patients undergoing transpedicular corpectomies had a greater recovery of neurological function than those in whom anterior-approach corpectomies were performed.

Conclusions
The transpedicular corpectomy appears to have a comparable morbidity rate to anterior-only corpectomies, but its morbidity rate is lower than that of anterior-posterior corpectomies.
Polyphenol oxidase activity in the roots of seedlings of Bromus (Poaceae) and other grass genera
Authors: Holzapfel Claus , Shahrokh Pouyan , Kafkewitz David 
Published: June 2010

• Premise of the study: Phenolic compounds exuded by roots have been implicated in allelopathic interactions among plants. Root enzymes that destroy phenolics may protect plants against allelopathic inhibition and thus may aid in invasiveness. Phenolic‐degrading enzymes are chiefly found in aboveground plant parts, but have also been previously reported in root tissues where the enzyme's function is unknown. We explored phenolic oxidase activity in emerging roots of grasses in a survey across different grass genera; in particular, we aimed to test whether grasses of the genus Bromus, known for their large invasion potential, differ in this respect from other grass taxa.• Methods: We assayed a range of grass genera commonly found in the United States for root enzyme activity with spectrophotometric assays of phenol oxidase activity using l‐DOPA as the main substrate.• Key results: In the survey of a grass genera, we discovered that roots of the genus Bromus contain large amounts of polyphenol oxidase (PPO) activity, while all other tested grass genera, even ones closely related to Bromus, did not. PPO was found to be present at germination and remained active throughout the life of the plant. Compared to other PPOs, the enzyme present in Bromus appears to have a narrow substrate range.• Conclusions: The specific functions of the root PPO and the ecological ramifications of the special status of Bromus are not yet clear. The possibility that the enzyme plays a role in plant species interaction for bromes, a genus of grasses known to have high invasive potential, is raised.
Cardiopulmonary Exercise Testing with Right-heart Catheterization in Patients with Systemic Sclerosis
Authors: WALKEY ALLAN J. , IEONG MICHAEL , ALIKHAN MIR , FARBER HARRISON W. 
Published: June 2010

Objective.To examine the role of cardiopulmonary exercise testing with right-heart catheterization (CPET/RHC) in patients with systemic sclerosis (SSc) with potentially multifactorial exertional limitation.Methods.This was a single-center retrospective cohort study of patients with SSc referred for CPET/RHC.Results.A total of 19 patients with SSc [subtypes: 10 limited, 5 diffuse, 1 systemic lupus erythematosus (SLE)/SSc overlap, and 3 with no subtype specified in the medical record] underwent CPET/RHC testing from February 2003 to February 2008. Of these patients, the primary limitations to exercise were found to be ventilatory (n = 6), deconditioning/cardiovascular (n = 6), pulmonary vascular (PVL; n = 3), and exercise-induced left ventricular diastolic dysfunction (exercise-LVDD; n = 4). No prior physical examination, pulmonary function test, imaging, or echocardiographic data reliably predicted the etiology of exercise limitation determined by CPET/RHC. Vital capacity and ventilatory equivalent for CO2 did not differ during CPET testing between PVL and exercise–LVDD, limiting the utility of CPET alone for discriminating these etiologies of dyspnea. Exercise alveolar-arterial oxygen gradient was elevated in subjects shown to have PVL [median 48 mm Hg (interquartile range 45.3, 62.0)] compared to those with exercise-LVDD [26.0 (IQR 10.6, 36.0)] and deconditioning [13.9 (IQR 4.0, 16.4); p = 0.02]. Major therapeutic changes occurred in 11/19 (58%) subjects after CPET/RHC testing.Conclusion.CPET/RHC testing in subjects with SSc and potentially multifactorial dyspnea adds potentially useful diagnostic information unavailable from noninvasive testing.
A Functional Relationship Between Watershed Size and Atlantic Salmon Parr Density
Authors: Sweka John A. , Mackey Gregory 
Published: June 2010

Abstract
Atlantic salmon Salmon salar are at critically low levels in Maine rivers and maintaining current populations depends heavily on the stocking of hatchery-produced fry. Fry survival varies greatly not only among rivers but also within rivers. Better understanding of this spatial variability is needed to improve population recovery efforts. Quantile regression was used to examine how parr density varies along stream gradients as a function of the upstream cumulative drainage. Regression quantiles (τ  =  0.15–0.90) had significant negative slopes indicating that, in general, as cumulative drainage area increased, parr density decreased. The τ  =  0.90 quantile model, which may be viewed as an upper limit to parr density for a given cumulative drainage area, was density  =  [10⁁(1.0679 − 0.0013 · km2)] − 1. Quantile regression models were then combined with river-specific habitat data in a Geographic Information System to predict total Atlantic salmon parr production in several rivers. This analysis will help managers determine the potential of a stream reach or entire river to support Atlantic salmon parr and to prioritize and increase the effectiveness of management activities such as fry stocking and habitat restoration.
Comparison of Agricultural Seed Loss in Flooded and Unflooded Fields on the Tennessee National Wildlife Refuge
Authors: Foster Melissa A. , Gray Matthew J. , Harper Craig A. , Walls Johnathan G. 
Published: June 2010

Abstract
Waterfowl exploit seed resources in agricultural fields to help meet the energy demands associated with migration, thermoregulation, and various life-history activities. Biologists commonly flood agricultural fields to increase the availability of seed for waterfowl and to provide hunting opportunities. Previous studies suggest that flooding may accelerate seed loss; however, simultaneous comparison of seed loss with unflooded fields has not been made. We compared rates of loss between seed contained in wire mesh bags placed in an unflooded agricultural field vs. seed submersed in a flooded field on the Tennessee National Wildlife Refuge from October 2007 to January 2008. Agricultural seed mass declined 40–300% more rapidly in the flooded than in the unflooded field. Corn, soybean, and grain sorghum seed mass declined 42%, 87%, and 46%, respectively, after 12 wk of continuous submersion, which was similar to previous studies that measured seed loss in flooded mesh bags. However, the rate of seed mass loss in unsubmersed mesh bags was 1.3–6.9 times lower than scattered seed lying on the ground under granivore exclosures in a separate experiment. We hypothesize lower rates of seed loss in mesh bags compared to scattered seed may be an artifact of the bags, which are commonly used in seed fate studies. Our results suggest biologists should delay flooding agricultural fields until immediately prior to the arrival of waterfowl and be aware that absolute estimates of seed loss from studies that use mesh bags may be biased negatively.
Red-Shouldered Hawk Nesting Habitat Preference in South Texas
Authors: Strobel Bradley N. , Boal Clint W. 
Published: June 2010

AbstractWe examined nesting habitat preference by red-shouldered hawks Buteo lineatus using conditional logistic regression on characteristics measured at 27 occupied nest sites and 68 unused sites in 2005–2009 in south Texas. We measured vegetation characteristics of individual trees (nest trees and unused trees) and corresponding 0.04-ha plots. We evaluated the importance of tree and plot characteristics to nesting habitat selection by comparing a priori tree-specific and plot-specific models using Akaike's information criterion. Models with only plot variables carried 14% more weight than models with only center tree variables. The model-averaged odds ratios indicated red-shouldered hawks selected to nest in taller trees and in areas with higher average diameter at breast height than randomly available within the forest stand. Relative to randomly selected areas, each 1-m increase in nest tree height and 1-cm increase in the plot average diameter at breast height increased the probability of selection by 85% and 10%, respectively. Our results indicate that red-shouldered hawks select nesting habitat based on vegetation characteristics of individual trees as well as the 0.04-ha area surrounding the tree. Our results indicate forest management practices resulting in tall forest stands with large average diameter at breast height would benefit red-shouldered hawks in south Texas.