bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Newspaper Content Analysis of HIV/AIDS and Food Insecurity in Sub‐Saharan Africa
Authors: MacPherson Jennifer L. , Wadsworth Laurie A. 
Published: September 2011

AbstractThis study sought to identify media links presented between food insecurity and the HIV pandemic in sub‐Saharan Africa through description of commonly portrayed frames found in high visibility Western and African print media sources. An episodic sampling process during the summer of 2006 found articles that tied food security to the HIV pandemic. Content analysis employed a mixed methodology grounded in naturalistic inquiry. Included were interpretative thematic analyses of text and images along with a frequency content coding instrument as a means of triangulation. Several themes emerged during analysis of the sample, including a biomedical frame, war and competition imagery, economic threats, food insecurity as a contributing factor for HIV infection, and hopeful action. Differences noted within Western and African print media framing of food security within the HIV pandemic consisted of an overall Western portrayal that was less actionable and more hopeless in nature than African portrayals. The potential of integrating existing frames and working towards newer frames is discussed as a method to improve citizen‐level action on global issues and further the agenda‐setting process necessary for policy development.
Changing the Risk Paradigms can be Good for Our Health: J-Shaped, Linear and Threshold Dose-Response Models
Authors: Ricci P. F. , Straja S. R. , Cox A. L. 
Published: September 2011

Both the linear (at low doses)-no-threshold (LNT) and the threshold models ( S-shapes) dose-response lead to no benefit from low exposure. We propose three new models that allow and include, but do not require – unlike LNT and S-shaped models — this strong assumption. We also provide the means to calculate benefits associated with bi-phasic biological behaviors, when they occur and propose: Three hormetic (phasic) models: the J-shaped, inverse J-shaped, the min-max, and Method for calculating the direct benefits associated with the J and inverse J-shaped models. The J-shaped and min-max models for mutagens and carcinogenic agents include an experimentally justified repair stage for toxic and carcinogenic damage. We link these to stochastic transition models for cancer and show how abrupt transitions in cancer hazard rates, as functions of exposure concentrations and durations, can emerge naturally in large cell populations even when the rates of cell-level events increase smoothly (e.g., proportionally) with concentration. In this very general family of models, J-shaped dose-response curves emerge. These results are universal, i.e., independent of specific biological details represented by the stochastic transition networks. Thus, using them suggests a more complete and realistic way to assess risks at low doses or dose-rates.
Association of Pretransplant Serum Phosphorus with Posttransplant Outcomes
Authors: Sampaio Marcelo S. , Molnar Miklos Z. , Kovesdy Csaba P. , Mehrotra Rajnish , Mucsi Istvan , Sim John J. , Krishnan Mahesh , Nissenson Allen R. , Kalantar-Zadeh Kamyar 
Published: September 2011

Summary

Background and objectives
Serum phosphorus levels are associated with mortality, cardiovascular disease, and renal function loss in individuals with and without chronic kidney disease. The association of pretransplant serum phosphorus levels with transplant outcomes is not clear.

Design, setting, participants, & measurements
Data of the Scientific Registry of Transplant Recipients (SRTR) up to June 2007 were linked to the database (2001 through 2006) of one of the U.S.-based large dialysis organizations (DaVita). The selected 9384 primary kidney recipients were divided into five groups according to pretransplant serum phosphorus levels (mg/dl): <3.5, 3.5 to <5.5 (reference group), 5.5 to <7.5, 7.5 to <9.5, and ≥9.5. Unadjusted and multivariate adjusted risks for transplant outcomes were compared.

Results
Patients were 48 ± 14 years old and included 37% women and 27% African Americans. After multivariate adjustment, all-cause and cardiovascular death hazard ratios were 2.44 (95% confidence interval: 1.28 to 4.65) and 3.63 (1.13 to 11.64), respectively, in recipients in the ≥9.5 group; allograft loss hazard ratios were 1.42 (1.04 to 1.95) and 2.36 (1.33 to 4.17) in recipients with 7.5 to >9.5 and ≥9.5, respectively. No significant association with delayed graft function was found.

Conclusions
Pretransplant phosphorus levels 7.5 to <9.5 mg/dl and ≥9.5 mg/dl were associated with increased risk of functional graft failure and increased risk of all-cause and cardiovascular deaths, respectively, when compared with 3.5 to <5.5 mg/dl. Additional studies are needed to examine whether more aggressive control of pretransplant serum phosphorus may improve posttransplant outcomes.
Accuracy of the freehand technique for 3 fixation methods in the C-2 vertebrae
Authors: Helgeson Melvin D. , Lehman Ronald A. , Dmitriev Anton E. , Kang Daniel G. , Sasso Rick C. , Tannoury Chadi , Riew K. Daniel 
Published: September 2011

Object
Intraoperative imaging often does not provide adequate visualization to ensure safe placement of screws. Therefore, the authors investigated the accuracy of a freehand technique for placement of pars, pedicle, and intralaminar screws in C-2.

Methods
Sixteen cadaveric specimens were instrumented freehand by 2 experienced cervical spine surgeons with either a pars or pedicle screw, and bilateral intralaminar screws. The technique was based on anatomical starting points and published screw trajectories. A pedicle finder was used to establish the trajectory, followed by tapping, palpation, and screw placement. After placement of all screws (16 pars screws, 16 pedicle screws, and 32 intralaminar screws), the C-2 segments were disarticulated, radiographed in anteroposterior, lateral, and axial planes, and meticulously inspected by another spine surgeon to determine the nature and presence of any defects.

Results
A total of 64 screws were evaluated in this study. Pars screws exhibited 2 critical defects (1 in the foramen transversarium and 1 in the C2–3 facet) and an insignificant dorsal cortex breech, for an overall accuracy rate of 81.3%. Pedicle screws demonstrated only 1 insignificant violation (inferior facet/medial cortex intrusion of 1 mm) with an accuracy rate of 93.8%, and intralaminar screws demonstrated 3 insignificant violations (2 in the ventral canal, 1 in the caudad lamina breech) for an accuracy rate of 90.6%. Pars screws had significantly more critical violations than intralaminar screws (p = 0.041).

Conclusions
Instrumentation of the C-2 vertebrae using the freehand technique for insertion of pedicle and intralaminar screws showed a high success rate with no critical violations. Pars screw insertion was not as reliable, with 2 critical violations from a total of 16 placements. The freehand technique appears to be a safe and reliable method for insertion of C-2 pedicle and intralaminar screws.
Pedicle screw loosening in dynamic stabilization: incidence, risk, and outcome in 126 patients
Authors: Wu Jau-Ching , Huang Wen-Cheng , Tsai Hsiao-Wen , Ko Chin-Chu , Wu Ching-Lan , Tu Tsung-Hsi , Cheng Henrich 
Published: September 2011

Object
The long-term outcome of lumbar dynamic stabilization is uncertain. This study aimed to investigate the incidence, risk factors, and outcomes associated with screw loosening in a dynamic stabilization system.

Methods
The authors conducted a retrospective review of medical records, radiological studies, and clinical evaluations obtained in consecutive patients who underwent 1- or 2-level lumbar dynamic stabilization and were followed up for more than 24 months. Loosening of screws was determined on radiography and CT scanning. Radiographic and standardized clinical outcomes, including the visual analog scale (VAS) and Oswestry Disability Index (ODI) scores, were analyzed with a focus on cases in which screw loosening occurred.

Results
The authors analyzed 658 screws in 126 patients, including 54 women (42.9%) and 72 men (57.1%) (mean age 60.4 ± 11.8 years). During the mean clinical follow-up period of 37.0 ± 7.1 months, 31 screws (4.7%) in 25 patients (19.8%) were shown to have loosened. The mean age of patients with screw loosening was significantly higher than those without loosening (64.8 ± 8.8 vs 59.3 ± 12.2, respectively; p = 0.036). Patients with diabetes mellitus had a significantly higher rate of screw loosening compared with those without diabetes (36.0% vs 15.8%, respectively; p = 0.024). Diabetic patients with well-controlled serum glucose (HbA1c ≤ 8.0%) had a significantly lower chance of screw loosening than those without well-controlled serum glucose (28.6% vs 71.4%, respectively; p = 0.021). Of the 25 patients with screw loosening, 22 cases (88%) were identified within 6.6 months of surgery; 18 patients (72%) had the loosened screws in the inferior portion of the spinal construct, whereas 7 (28%) had screw loosening in the superior portion of the construct. The overall clinical outcomes at 3, 12, and 24 months, measured by VAS for back pain, VAS for leg pain, and ODI scores, were significantly improved after surgery compared with before surgery (all p < 0.05). There were no significant differences between the patients with and without screw loosening at all evaluation time points (all p > 0.05). All 25 patients with screw loosening were asymptomatic, and in 6 (24%) osseous integration was demonstrated on later follow-up. Also, there were 3 broken screws (2.38% in 126 patients or 0.46% in 658 screws). To date, none of these loosened or broken screws have required revision surgery.

Conclusions
Screw loosening in dynamic stabilization systems is not uncommon (4.7% screws in 19.8% patients). Patients of older age or those with diabetes have higher rates of screw loosening. Screw loosening can be asymptomatic and presents opportunity for osseous integration on later follow-up. Although adverse effects on clinical outcomes are rare, longer-term follow-up is required in cases in which screws become loose.
Complications related to instrumentation in spine surgery: a prospective analysis
Authors: Campbell Peter G. , Yadla Sanjay , Malone Jennifer , Maltenfort Mitchell G. , Harrop James S. , Sharan Ashwini D. , Ratliff John K. 
Published: September 2011

Object
Prospective examination of perioperative complications in spine surgery is limited in the literature. The authors prospectively collected data on patients who underwent spinal fusion at a tertiary care center and evaluated the effect of spinal fusion and comorbidities on perioperative complications.

Methods
Between May and December 2008 data were collected prospectively in 248 patients admitted to the authors' institution for spine surgery. The 202 patients undergoing spine surgery with instrumentation were further analyzed in this report. Perioperative complications occurring within the initial 30 days after surgery were included. All adverse occurrences, whether directly related to surgery, were included in the analysis.

Results
Overall, 114 (56.4%) of 202 patients experienced at least one perioperative complication. Instrumented fusions were associated with more minor complications (p = 0.001) and more overall complications (0.0024). Furthermore, in the thoracic and lumbar spine, complications increased based on the number of levels fused. Advanced patient age and certain comorbidities such as diabetes, cardiac disease, or a history of malignancy were also associated with an increased incidence of complications.

Conclusions
Using a prospective methodology with a broad definition of complications, the authors report a significantly higher perioperative incidence of complications than previously indicated after spinal fusion procedures. Given the increased application of instrumentation, especially for degenerative disease, a better estimate of clinically relevant surgical complications could aid spine surgeons and patients in an individualized complication index to facilitate a more thorough risk-benefit analysis prior to surgery.
Features of the lumbar spine on magnetic resonance images following sectioning of filum terminale
Authors: Kim Albert H. , Kasliwal Manish K. , McNeish Brendan , Silvera V. Michelle , Proctor Mark R. , Smith Edward R. 
Published: September 2011

Object
Spinal cord tethering due to a thickened filum terminale is a well-described entity that can be treated surgically. Postoperative MR imaging of the lumbar spine is performed for unrelated issues or for the development of new symptoms suggestive of cord retethering. A lack of radiological criteria for successful detethering makes interpretation of postoperative MR images challenging. The delineation of postoperative radiological characteristics of a sectioned filum terminale is therefore valuable to clinicians managing these often complex cases.

Methods
The clinical data for 16 patients who underwent sectioning of a fatty and thickened filum between 2001 and 2010 and in whom pre- and postoperative MR imaging studies were available were analyzed. Medical records were interrogated for preoperative neurological examination, operative details, and postoperative follow-up. The MR images were examined by both a neurosurgeon and a neuroradiologist to assess postoperative radiological characteristics.

Results
The patients' age at time of surgery ranged from 0.3 to 19.8 years (mean 7.5 years). Postoperative MR imaging was performed between 0.03 and 7.36 years after the procedure (mean 2.5 years). Indications for postoperative imaging included new neurological symptoms (11 of 16 patients), routine interval imaging (3 of 16), and possible development of pseudomeningocele (2 of 16). Filum discontinuity was confirmed in 79% of cases postoperatively. Filum remnants appeared thicker after surgery in most cases (80%), a phenomenon most often appreciated in the cephalad end of the sectioned filum. Postoperatively, the conus was elevated in 5 cases (31%) and was found to be more ventrally located in 7 cases (44%).

Conclusions
Discontinuity, along with thickening of the upper and lower remnants of a sectioned filum, may constitute important radiological features of a detethered filum. Radiological signs of conus relaxation, signified by elevation or a more ventral position, although reassuring, were less reliably observed postoperatively. Because it may be difficult to know if the goals of surgery were met on purely clinical grounds in this patient population, knowledge of the postoperative characteristics of a sectioned filum may aid the practicing neurosurgeon in the management of these complex cases.
Atlantal hemi-rings and craniocervical instability: identification, clinical characteristics, and management
Authors: Brockmeyer Douglas L. , Brockmeyer Meghan M. , Bragg Taryn 
Published: September 2011

Object
Congenital craniovertebral anomalies are relatively common, but anomalies leading to overt craniocervical instability may be difficult to recognize and treat. The authors present a series of patients with atlantal hemi-rings, a disorder resulting in congenital craniovertebral instability. Presentation, treatment, imaging, and follow-up data obtained in patients with atlantal hemi-rings were assessed to identify factors relevant to craniocervical instability.

Methods
Nineteen patients were identified with atlantal hemi-rings, defined as a bony discontinuity of the C-1 ring in conjunction with lateral displacement of the C-1 lateral masses (as seen on coronal CT scans). Clinical and radiological characteristics were analyzed, including patient age at presentation, extent of occipitocervical motion, amount of C-1 lateral mass displacement, associated craniocervical anomalies, integrity of the transverse ligament, and neurological status.

Results
The mean patient age at presentation was 22 months (range birth to 9 years). The mean amount of occipitocervical translation seen on dynamic imaging was 9 mm (range 2–20 mm). Four patients required occipitocervical fusion at presentation. The remaining 15 patients were monitored for a mean of 20 months, and 9 ultimately underwent fusion. Surgery was also recommended for 4 of the remaining 6 children.

Conclusions
This report describes the radiological and clinical characteristics of patients with atlantal hemirings and craniocervical instability. The authors believe that this anomaly is the underlying cause of progressive instability in a significant proportion of patients with craniocervical abnormalities. The presence of atlantal hemi-rings should prompt immediate and thorough neurosurgical evaluation.
Management of Dandy-Walker complex–associated infant hydrocephalus by combined endoscopic third ventriculostomy and choroid plexus cauterization
Authors: Warf Benjamin C. , Dewan Michael , Mugamba John 
Published: September 2011

Object
Dandy-Walker complex (DWC) is a continuum of congenital anomalies comprising Dandy-Walker malformation (DWM), Dandy-Walker variant (DWV), Blake pouch cyst, and mega cisterna magna (MCM). Hydrocephalus is variably associated with each of these, and DWC-associated hydrocephalus has mostly been treated by shunting, often with 2-compartment shunting. There are few reports of management by endoscopic third ventriculostomy (ETV). This study is the largest series of DWC or DWM-associated hydrocephalus treated by ETV, and the first report of treatment by combined ETV and choroid plexus cauterization (ETV/CPC) in young infants with this association.

Methods
A retrospective review of the CURE Children's Hospital of Uganda clinical database between 2004 and 2010 identified 45 patients with DWC confirmed by CT scanning (25 with DWM, 17 with DWV, and 3 with MCM) who were treated for hydrocephalus by ETV/CPC. Three were excluded because of other potential causes of hydrocephalus (2 postinfectious and 1 posthemorrhagic).

Results
The median age at treatment was 5 months (88% of patients were younger than 12 months). There was a 2.4:1 male predominance among patients with DWV. An ETV/CPC (ETV only in one) was successful with no further operations in 74% (mean and median follow-up 24.2 and 20 months, respectively [range 6–65 months]). The rate of success was 74% for DWM, 73% for DWV, and 100% for MCM; 95% had an open aqueduct, and none required posterior fossa shunting.

Conclusions
Endoscopic treatment of DWC-associated hydrocephalus should be strongly considered as the primary management in place of the historical standard of creating shunt dependence.
Revision strategies for AxiaLIF
Authors: Hofstetter Christoph P. , James Andrew R. , Härtl Roger 
Published: September 2011

Object
Paracoccygeal transsacral fixation is a novel percutaneous technique for arthrodesis of L5–S1 and L4–5 (Axial Lumbar Interbody Fusion [AxiaLIF]). There are no reports on feasible revision strategies. The goal of this paper is to analyze the surgical details of failed AxiaLIF constructs and to describe revision strategies.

Methods
The medical charts, operative records, and imaging studies of 5 patients with failed multisegment instrumentation using the AxiaLIF device were reviewed.

Results
AxiaLIF constructs were revised in 5 patients with a mean age of 58.4 years. All AxiaLIF devices were part of multisegment fusion constructs for revision surgery and were revised an average of 15 months after implantation. Two AxiaLIF devices were percutaneously retrieved; one because of excessive bone resorption around the AxiaLIF screw, and the other because of chronic hardware infection. In these 2 patients, the anterior column was subsequently stabilized via anterior lumbar interbody fusion. In the other 3 patients, the AxiaLIF device was left in situ. In 2 of these patients the anterior column was stabilized with bilateral L5–S1 posterior lumbar interbody fusion, and in the remaining patient with L4–5 instability the posterior instrumentation only was revised. Revision surgeries were well tolerated. One patient suffered from a wound dehiscence of the back wound.

Conclusions
AxiaLIF devices are safely retrieved using percutaneous technique. Both anterior and posterior revision strategies may be used to achieve anterior column fixation.
Anterior corpectomy versus posterior laminoplasty: is the risk of postoperative C-5 palsy different?
Authors: Gandhoke Gurpreet , Wu Jau-Ching , Rowland Nathan C. , Meyer Scott A. , Gupta Camilla , Mummaneni Praveen V. 
Published: September 2011

Object
Both anterior cervical corpectomy and fusion (ACCF) and laminoplasty are effective treatments for selected cases of cervical stenosis. Postoperative C-5 palsies may occur with either anterior or posterior decompressive procedures; however, a direct comparison of C-5 palsy rates between the 2 approaches is not present in the literature. The authors sought to compare the C-5 palsy rate of ACCF versus laminoplasty.

Methods
The authors conducted a retrospective review of 31 ACCF (at C-4 or C-5) and 31 instrumented laminoplasty cases performed to treat cervical stenosis. The demographics of the groups were similar except for age (ACCF group mean age 53 years vs laminoplasty group mean age 62 years, p = 0.002). The mean number of levels treated was greater in the laminoplasty cohort (3.87 levels) than in the ACCF cohort (2.74 levels, p < 0.001). The mean preoperative Nurick grade of the laminoplasty cohort (2.61) was higher than the mean preoperative Nurick grade of the ACCF cohort (1.10, p < 0.001).

Results
The overall clinical follow-up rate was 100%. The mean overall clinical follow-up was 15 months. There were no significant differences in the estimated blood loss or length of stay between the 2 groups (p > 0.05). There was no statistical difference between the complication or reoperation rates between the 2 groups (p = 0.184 and p = 0.238). There were 2 C-5 nerve root pareses in each group. Three of the 4 patients recovered full deltoid function, and the fourth patient recovered nearly full deltoid function at final follow-up. There was no statistical difference in the rate of deltoid paresis (6.5%) between the 2 groups (p = 1).

Conclusions
Both ACCF and laminoplasty are effective treatments for patients with cervical stenosis. The authors found no difference in the rate of deltoid paresis between ACCF and laminoplasty to treat cervical stenosis.