bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of vitamin E on pathological changes in kidney and liver of sulphur mustard-exposed guinea pigs
Authors: Boskabady Mohammad Hossein , Tabatabayee Abbas , Amiri Sediqa , Vahedi Nasim
Published: October 2011

Sulphur mustard (SM) gas is a poisonous chemical agent causing various systemic action in laboratory animals. There is no definite treatment for disorders induced by SM. In this study, the effect of vitamin E alone and in combination with dexamethasone on the pathological changes in the kidney and liver of SM-exposed (SME) guinea pigs was examined. Guinea pigs were divided into five groups ( n = 5 in each). These groups were exposed to ethanol (control group), 100 mg/m3 inhaled SM (SME group), SME treated with vitamin E, 600 mg/kg (SME + E), SME treated with dexamethasone, 5 mg/kg (SME + D), and SME treated with both drugs (SME + E + D), respectively. Pathological evaluation of the kidneys and livers was done 14 days post exposure. There were statistically significant pathological changes in the liver and kidney of SME group compared to control animals ( p < 0.05 to p < 0.001). Treatment of SME animals with vitamin E, dexamethasone and their combination caused statistically significant improvement in the pathological changes in the livers and kidneys ( p < 0.05 to p < 0.001). These results showed a preventive effect of vitamin E on pathological changes in the liver and more prominently in the kidneys of SME guinea pigs.
American Childhood Football as a Possible Risk Factor for Cerebral Infarction
Authors: Brosch Jared R. , Golomb Meredith R.
Published: October 2011

Three adolescent football players who had ischemic stroke associated with football practice and play are described. The literature on stroke associated with childhood sports and football in particular is reviewed, and the multiple mechanisms by which football can contribute to ischemic stroke are discussed.
Distancing as a Gendered Barrier
Authors: Rhoton Laura A.
Published: October 2011

Gendered barriers to women’s advancement in STEM disciplines are subtle, often the result of gender practices, gender stereotypes, and gendered occupational cultures. Professional socialization into scientific cultures encourages and rewards gender practices that help to maintain gendered barriers. This article focuses more specifically on how individual women scientists’ gender practices potentially sustain gender barriers. Findings based on interview data from thirty women in academic STEM fields reveal that women draw on gendered expectations and norms within their disciplines to discursively distance themselves from other women they perceive as having deviated from such norms and expectations. The types of distancing in which these respondents engage reflect and support gendered structures, cultures, and practices that ultimately disadvantage women and obscure gender inequality. I conclude by discussing the implications of women scientists’ distancing practices for efforts to change the gendered cultures of STEM disciplines.
Characterization of the distribution-nozzle operation for mixture homogenization by a late-diesel-injection strategy
Authors: Weclas M , Cypris J
Published: October 2011

In order to realize a homogeneous combustion process it is necessary to decouple this combustion process from fuel injection. This homogeneous combustion process requires the charge to be homogeneous prior to simultaneous volumetric ignition. This kind of ignition is a self-ignition process requiring control of the ignition timing. A late-injection strategy as used in a conventional diesel engine permits control of the ignition timing; however, the time available for mixture formation and the homogenization process is very limited. The present paper deals with a distribution-nozzle concept which combines both strategies: a late-injection strategy for controlling the ignition timing with significantly accelerated fuel distribution in space and corresponding mixture homogenization. The distribution-nozzle concept combines a conventional diesel nozzle with a porous element (ring) positioned in proximity to the nozzle outlet. Because of multi-jet splitting as a result of the diesel-jet interaction with a porous structure, the fuel leaving the porous ring spreads widely in space. Additionally, a very effective fuel vaporization process occurs within the porous structure, supporting quick mixture formation. The paper describes both the fuel distribution in space and its vaporization for different configurations of the distribution elements, the injection pressure, and the porous ring temperature. In comparison with a free diesel injection, the distribution nozzle results in a significantly increased fuel surface area, a reduced jet penetration length, a reduced jet velocity, and very quick fuel vaporization. This process is three dimensional in nature. Depending on the distribution-element structure, the geometry, and its temperature, as well as the injection pressure, the contributions of multi-jet splitting, and fuel vaporization, are different with respect to the surface area, penetration length, and exit velocity, as well as intensity distribution. Generally, at higher injection pressures these parameters are less temperature dependent, except for the fact that the intensity distribution is a function of the fuel vapour’s concentration.
Analysis of the railway track as a spatially periodic structure
Authors: García-Palacios J , Samartín A , Melis M
Published: October 2011

This article presents a new and computationally efficient method of analysis of a railway track modelled as a continuous beam of 2 N spans supported by elastic vertical springs. The main feature of this method is its important reduction in computational effort with respect to standard matrix methods of structural analysis. In this article, the whole structure is considered to be a repetition of a single one. The analysis presented is applied to a simple railway track model, i.e. to a repetitive beam supported on vertical springs (sleepers). The proposed method of analysis is based on the general theory of spatially periodic structures. The main feature of this theory is the possibility to apply Discrete Fourier Transform (DFT) in order to reduce a large system of q(2 N + 1) linear stiffness equilibrium equations to a set of 2 N + 1 uncoupled systems of q equations each. In this way, a dramatic reduction of the computational effort of solving the large system of equations is achieved. This fact is particularly important in the analysis of railway track structures, in which N is a very large number (around several thousands), and q = 2, the vertical displacement and rotation, is very small. The proposed method allows us to easily obtain the exact solution given by Samartín [ 1 ], i.e. the continuous beam railway track response. The comparison between the proposed method and other methods of analysis of railway tracks, such as Lorente de Nó and Zimmermann-Timoshenko, clearly shows the accuracy of the obtained results for the proposed method, even for low values of N. In addition, identical results between the proposed and the Lorente methods have been found, although the proposed method seems to be of simpler application and computationally more efficient than the Lorente one. Small but significative differences occur between these two methods and the one developed by Zimmermann-Timoshenko. This article also presents a detailed sensitivity analysis of the vertical displacement of the sleepers. Although standard matrix methods of structural analysis can handle this railway model, one of the objectives of this article is to show the efficiency of DFT method with respect to standard matrix structural analysis. A comparative analysis between standard matrix structural analysis and the proposed method (DFT), in terms of computational time, input, output and also software programming, will be carried out. Finally, a URL link to a MatLab computer program list, based on the proposed method, is given
Discrete Trial Teaching
Authors: Gongola Leah , Sweeney Jennifer
Published: October 2011

Current special education law mandates that educators use scientifically based practices, and in addition, educators should deliver refined instruction for learners with disabilities. Applied behavior analysis, based on the premise of increasing socially significant behaviors, embodies many interventions that adhere to evidence-based teaching practices. Discrete trial teaching is an intervention that can be implemented in the classroom setting and has been found to have strong benefits for students when the practice is delivered with consistency. This article offers classroom implementation instructions paired with validation for implementing discrete trial teaching when working with students with autism and other exceptionalities.
Prospective Validity of the Estimate of Risk of Adolescent Sexual Offense Recidivism (ERASOR)
Authors: Worling James R. , Bookalam David , Litteljohn Ariel
Published: October 2011

Data from the Estimate of Risk of Adolescent Sexual Offense Recidivism (ERASOR; Worling & Curwen) were collected for a sample of 191 adolescent males who had offended sexually. Adolescents were aged 12 to 19 years ( M = 15.34; SD = 1.53) at the time of their participation in a comprehensive assessment. The ERASOR was completed by 1 of 22 clinicians immediately following each assessment. Forty-five adolescents were independently rated by pairs of clinicians, and significant interrater agreement was found for the ERASOR risk factors, the clinical judgment ratings ( low, moderate, or high), and a total score. Recidivism data (criminal charges) were subsequently collected from three sources that spanned a follow-up period between 0.1 and 7.9 years ( M = 3.66; SD = 2.08). Overall, 9.4% (18 of 191) of the adolescents were charged with a subsequent sexual offense over this time period. A shorter follow-up interval of up to 2.5 years ( M = 1.4; SD = 0.71) was also examined. Recidivism data for the shorter follow-up interval were available for a subgroup of 70 adolescents, with a comparable recidivism rate of 8.6% (6 of 70). Clinical judgment ratings, the total score, and the sum of risk factors rated as present were significantly predictive of sexual reoffending for the short follow-up period. The total score and the sum of risk factors were predictive of sexual reoffending over the entire follow-up interval. These results add to the emerging research supporting the reliability and validity of structured risk assessment tools for adolescent sexual recidivism.
Representations of health and illness by Eastern European, South American and Italian care workers: a qualitative study
Authors: Pace Cecilia Serena , Velotti Patrizia , Zavattini Giulio Cesare
Published: October 2011

This qualitative research examined the representations of health and illness presented by 30 individuals who work as care workers, from three different locations: Eastern Europe, South America and Italy. We led three focus groups for people who came from the same geographical area (intra-ethnic) and two for those from ‘mixed’ areas (inter-ethnic). From our content analyses, certain similarities and differences between the conceptualizations of health and illness emerged: in the intra-ethnic focus groups, Eastern Europeans focused on ‘inner strengths’, South Americans on ‘love’ and Italians on ‘personal autonomy’. These peculiar traits were levelled in the inter-ethnic focus groups.
A Look at the Relationship between Service Failures, Guest Satisfaction, and Repeat-Patronage Intentions of Casual Dining Guests
Authors: Susskind Alex , Viccari Anthony
Published: October 2011

Service recovery is essential to maintaining guest satisfaction in the event of a service failure. However, restaurateurs must approach service recovery in the appropriate context, because guests give differential consideration to different types of problems. Without doubt, a restaurant’s failure to serve food correctly is viewed as the most serious type of failure, and a food problem coupled with a servicet failure makes matters even worse. However, service failures by themselves are soon forgiven if the recovery is properly handled. Oddly, the least important type of failure, that of atmosphere (e.g., design, noise level), is most likely to cause a guest never to return, even if the restaurant makes a proper recovery. This study of more than eight hundred restaurant patrons found a positive and significant association between guests’ reported satisfaction with the outcome of their complaint and their repeat patronage intentions. The study’s findings highlight the importance of adequately resolving guests’ complaints with the goal of increasing the possibility that the guest will return to a restaurant after a service (or food) failure.
Donor-specific anti-HLA Abs and graft failure in matched unrelated donor hematopoietic stem cell transplantation
Authors: Ciurea Stefan O. , Thall Peter F. , Wang Xuemei , Wang Sa A. , Hu Ying , Cano Pedro , Aung Fleur , Rondon Gabriela , Molldrem Jeffrey J. , Korbling Martin , Shpall Elizabeth J. , de Lima Marcos , Champlin Richard E. , Fernandez-Vina Marcelo
Published: October 2011

Anti-HLA donor-specific Abs (DSAs) have been reported to be associated with graft failure in mismatched hematopoietic stem cell transplantation; however, their role in the development of graft failure in matched unrelated donor (MUD) transplantation remains unclear. We hypothesize that DSAs against a mismatched HLA-DPB1 locus is associated with graft failure in this setting. The presence of anti-HLA Abs before transplantation was determined prospectively in 592 MUD transplantation recipients using mixed-screen beads in a solid-phase fluorescent assay. DSA identification was performed using single-Ag beads containing the corresponding donor's HLA-mismatched Ags. Anti-HLA Abs were detected in 116 patients (19.6%), including 20 patients (3.4%) with anti-DPB1 Abs. Overall, graft failure occurred in 19 of 592 patients (3.2%), including 16 of 584 (2.7%) patients without anti-HLA Abs compared with 3 of 8 (37.5%) patients with DSA (P = .0014). In multivariate analysis, DSAs were the only factor highly associated with graft failure (P = .0001; odds ratio = 21.3). Anti-HLA allosensitization was higher overall in women than in men (30.8% vs 12.1%; P < .0001) and higher in women with 1 (P = .008) and 2 or more pregnancies (P = .0003) than in men. We conclude that the presence of anti-DPB1 DSAs is associated with graft failure in MUD hematopoietic stem cell transplantation.
Randomized, Double-Blind, Placebo-Controlled Phase II Study of Single-Agent Oral Talactoferrin in Patients With Locally Advanced or Metastatic Non–Small-Cell Lung Cancer That Progressed After Chemotherapy
Authors: Parikh Purvish M. , Vaid Ashok , Advani Suresh H. , Digumarti Raghunadharao , Madhavan Jayaprakash , Nag Shona , Bapna Ajay , Sekhon Jagdev S. , Patil Shekhar , Ismail Preeti M. , Wang Yenyun , Varadhachary Atul , Zhu Junming , Malik Rajesh
Published: October 2011

Purpose

To investigate the activity and safety of oral talactoferrin (TLF) in patients with stages IIIB to IV non–small-cell lung cancer (NSCLC) for whom one or two prior lines of systemic anticancer therapy had failed.

Patients and Methods

Patients (n = 100) were randomly assigned to receive either oral TLF (1.5 g in 15 mL phosphate-based buffer) or placebo (15 mL phosphate-based buffer) twice per day in addition to supportive care. Oral TLF or placebo was administered for a maximum of three 14-week cycles with dosing for 12 consecutive weeks followed by 2 weeks off. The primary objective was overall survival (OS) in the intent-to-treat (ITT) patient population. Secondary objectives included progression-free survival (PFS), disease control rate (DCR), and safety.

Results

TLF was associated with improvement in OS in the ITT patient population, meeting the protocol-specified level of significance of a one-tailed P = .05. Compared with the placebo group, median OS increased by 65% in the TLF group (3.7 to 6.1 months; hazard ratio, 0.68; 90% CI, 0.47 to 0.98; P = .04 with one-tailed log-rank test). Supportive trends were also observed for PFS and DCR. TLF was well tolerated and, generally, there were fewer adverse events (AEs) and grade ≥ 3 AEs reported in the TLF arm. AEs were consistent with those expected in late-stage NSCLC.

Conclusion

TLF demonstrated an apparent improvement in OS in patients with stages IIIB to IV NSCLC for whom one or two prior lines of systemic anticancer therapy had failed and was well tolerated. These results should be confirmed in a global phase III trial.
Prognostic Value of the Stage 4S Metastatic Pattern and Tumor Biology in Patients With Metastatic Neuroblastoma Diagnosed Between Birth and 18 Months of Age
Authors: Taggart Denah R. , London Wendy B. , Schmidt Mary Lou , DuBois Steven G. , Monclair Tom F. , Nakagawara Akira , De Bernardi Bruno , Ambros Peter F. , Pearson Andrew D.J. , Cohn Susan L. , Matthay Katherine K.
Published: October 2011

Purpose

Patients with neuroblastoma younger than 12 months of age with a 4S pattern of disease (metastases limited to liver, skin, bone marrow) have better outcomes than infants with stage 4 disease. The new International Neuroblastoma Risk Group (INRG) staging system extends age to 18 months for the 4S pattern. Our aim was to determine which prognostic features could be used for optimal risk classification among patients younger than 18 months with metastatic disease.

Methods

Event-free survival (EFS) and overall survival were analyzed by log-rank tests, Cox models, and survival tree regression for 656 infants with stage 4S neuroblastoma younger than 12 months of age and 1,019 patients with stage 4 disease younger than 18 months of age in the INRG database.

Results

Unfavorable biologic features were more frequent in infants with stage 4 disease than in infants with 4S tumors and higher overall in those age 12 to 18 months (although not different for stage 4 v 4S pattern). EFS was significantly better for infants younger than 12 months with 4S pattern than with stage 4 disease (P < .01) but similar for toddlers age 12 to 18 months with stage 4 versus 4S pattern. Among 717 patients with stage 4S pattern, patients age 12 to 18 months had worse EFS than those age younger than 12 months (P < .01). MYCN, 11q, mitosis-karyorrhexis index (MKI), ploidy, and lactate dehydrogenase were independently statistically significant predictors of EFS and more highly predictive than age or metastatic pattern. MYCN, 11q, MKI, histology, and 1p were combined in a survival tree for improved risk stratification.

Conclusion

Tumor biology is more critical than age or metastatic pattern for prognosis of patients age younger than 18 months with metastatic neuroblastoma and should be considered for risk stratification.
Neurosurgical Management and Prognosis of Patients With Glioblastoma That Progresses During Bevacizumab Treatment
Authors: Clark Aaron J. , Lamborn Kathleen R. , Butowski Nicholas A. , Chang Susan M. , Prados Michael D. , Clarke Jennifer L. , McDermott Michael W. , Parsa Andrew T. , Berger Mitchel S. , Aghi Manish K.
Published: October 2011

BACKGROUND:

The management and prognosis of glioblastoma patients after Stupp protocol treatment and progression during bevacizumab (BV) treatment remain undefined.

OBJECTIVE:

We compared the morbidity and survival of patients whose glioblastomas progressed during BV treatment requiring craniotomy with those of patients not treated with BV.

METHODS:

We retrospectively reviewed patients who underwent craniotomy for recurrent glioblastoma from 2005 to 2009. Patients operated on for progression during BV (preoperative BV) were compared with patients receiving no BV or receiving BV after surgery (postoperative BV). Patients receiving BV preoperatively were compared with those patients whose gliobastoma progressed on BV treatment but were not operated on (no surgery).

RESULTS:

There were 23 preoperative BV patients, 135 no BV patients, 16 postoperative BV patients, and 25 no surgery patients. Patients receiving BV preoperatively had a worse postoperative overall survival rate (hazard ratio, 3.1; P < .001) and worse postoperative progression-free survival rate (hazard ratio, 3.4, P < .001) than patients not receiving BV. Patients receiving BV preoperatively had a higher perioperative morbidity rate (44%) than patients not receiving preoperative BV (21%) (P = 0.02). Survival after diagnosis was comparable between groups (86–93 weeks, P = .9), consistent with glioblastomas developing BV evasion being not intrinsically more aggressive, but possibly BV evasion conferring a uniquely poor prognosis. No surgery patients had a shorter overall survival after progression during BV treatment compared with preoperative BV patients (hazard ratio, 3.6, P < .001).

CONCLUSION:

Patients whose glioblastomas progress while receiving BV leading to craniotomy exhibit shorter postoperative survival and more perioperative morbidity than patients not treated with BV. Although there may be benefits to surgical debulking, the decision to pursue repeat surgery in patients in whom BV treatment failed must be balanced against the increased risk of perioperative complications.
Ventriculoperitoneal Shunt Surgery Outcome in Adult Transition Patients With Pediatric-Onset Hydrocephalus
Authors: Reddy G. Kesava , Bollam Papireddy , Caldito Gloria , Guthikonda Bharat , Nanda Anil
Published: October 2011

BACKGROUND:

Ventriculoperitoneal shunting remains the most widely used neurosurgical procedure for the management of hydrocephalus, albeit with many complications.

OBJECTIVE:

To review and assess the long-term clinical outcome of ventriculoperitoneal shunt surgery in adult transition patients with pediatric-onset hydrocephalus.

METHODS:

Patients 17 years or older who underwent ventriculoperitoneal shunt placement for hydrocephalus during their pediatric years (younger than 17 years) were included. Medical charts, operative reports, imaging studies, and clinical follow- up evaluations were reviewed and analyzed retrospectively.

RESULTS:

A total of 105 adult patients with pediatric-onset hydrocephalus were included. The median age of the patients was 25.9 years. The median age at the time of the initial ventriculoperitoneal shunt placement was 1.0 year. The median follow-up time for all patients was 17.7 years. The incidence of shunt failure at 6 months was 15.2%, and the overall incidence of shunt failure was 82.9%. Single shunt revision occurred in 26.7% of the patients, and 56.2% had multiple shunt revisions. The cause of hydrocephalus was significantly associated with shunt survival for patients who had shunt failure before the age of 17 years. Being pediatric at first shunt revision, infection, proximal shunt complication, and other causes were independently associated with multiple shunt failures.

CONCLUSION:

The findings of this retrospective study show that the long-term ventriculoperitoneal shunt survival remains low in adult transition patients with pediatric-onset hydrocephalus.
Correlation Between Persistent Neurological Impairment and Clinical Outcome After Microdiscectomy for Treatment of Lumbar Disc Herniation
Authors: Righesso Orlando , Falavigna Asdrubal , Avanzi Osmar
Published: October 2011

BACKGROUND:

Outcome of lumbar disc herniation is often based on clinical scores and less frequently on the neurological examination. However, even when clinical outcome measures are favorable, patients may still experience motor or sensory impairment.

OBJECTIVE:

To evaluate the percentage of patients with persistent neurological deficits after lumbar disc surgery and whether these correlate with clinical outcome.

METHODS:

A total of 150 patients with sciatica and lumbar disc herniation with neurological impairment underwent microdiscectomy and were prospectively followed for 24 months. Patients were assessed pre- and postoperatively with neurological examination, the Oswestry Disability Index (ODI), and the visual analog scale (VAS) for pain.

RESULTS:

Twenty-four months after surgery, 25% of patients who presented with motor deficits, 40% of patients with sensory deficits, and 48% of patients with reflex abnormalities remained unchanged. The VAS and the ODI showed significant improvement in both patients with and without persistent neurological impairment immediately after surgical repair of the herniated disc with progressive improvement over the follow-up period. However, when calculating the area under the receiver operating characteristics curve, no statistically significant correlation could be established between the presence and persistence of neurological impairment and the 2 clinical scores.

CONCLUSION:

There seems to be no correlation between clinical results and neurological impairment when assessed by the VAS and ODI.
Surgical Treatment of Low-Grade Isthmic Spondylolisthesis With Transsacral Fibular Strut Grafts
Authors: Passias Peter G. , Kozanek Michal , Wood Kirkham B.
Published: October 2011

Background:

The ideal surgical treatment for adult low-grade isthmic spondylolisthesis (ALIS) remains unknown. Isolated anterior and posterior procedures are popular but have resulted in equivocal outcomes, whereas combined anterior and posterior procedures are associated with higher complication rates despite improved outcome.

Objective:

To evaluate the clinical and radiographic outcomes following the treatment of ALIS using a 1-stage posterior approach with posterior decompression and posterolateral arthrodesis combined with an interbody fibular allograft strut.

Methods:

Fifteen patients underwent fusion by a single surgeon using our modified technique. Seven patients were female and 8 were male, with a mean age of 48 years. All patients were classified as Meyerding grade II slips and underwent a posterior approach only, a decompressive laminectomy, and a circumferential fusion with the use of a transsacral fibular allograft and a posterolateral instrumented fusion. Postoperative clinical and radiographic evaluations were performed at 3, 6, and 12 months, and then on an annual basis.

Results:

The average follow-up interval was 61 months. Three complications were seen: a single dural tear, an L5 radiculopathy secondary to a malpositioned pedicle screw, and one patient with urinary retention. The spines of all patients were determined to be fused by the 6-month postoperative visit. All patients returned to their normal activities of daily living. Significant improvements in the visual analog score were seen at all follow-up intervals.

Conclusion:

Transsacral interbody fibular allograft can be used successfully to supplement a posterolateral instrumented fusion in selected patients with low-grade ALIS.
Management of Residual and Recurrent Aneurysms After Initial Endovascular Treatment
Authors: Dorfer Christian , Gruber Andreas , Standhardt Harald , Bavinzski Gerhard , Knosp Engelbert
Published: October 2011

Background:

Coil instability possibly translating into higher delayed rebleeding rates remains a concern in the endovascular management of cerebral aneurysms.

Objective:

To report on 127 patients with endovascular aneurysmal remnants who underwent re-treatment over an 18 year period.

Methods:

Patients presenting with aneurysm residuals >20% of the original lesion, unstable neck remnants, aneurysmal regrowth, or new aneurysmal daughter sacs were treated by an individualized approach, using both endovascular and surgical techniques.

Results:

Seventy-five aneurysmal remnants (59.1%) were treated by further re-embolization. Standard coil embolization was used in 65 cases, stent-protected coiling in 9 cases, and balloon remodeled coiling in 1 case, respectively. Fifty-two (40.9%) aneurysmal remnants were treated surgically. Standard microsurgical clipping was used in 44 patients, parent artery occlusion or trapping under bypass protection in 5 cases, deliberate clipping of the basilar artery trunk in 2 cases, and aneurysm wrapping in one case, respectively. Mechanisms of aneurysm recurrence were coil compaction in 93 cases and regrowth in 34 cases. A single reembolization was sufficient to occlude 78.7% of recurrences from coil compaction, but only 14.3% of recurrences from aneurysm regrowth.

Conclusion:

The individualized approach resulted in complete occlusion of 114 aneurysms (89.7%), with neck remnants and residual aneurysms detectable in 11 (8.7%) and 2 (1.6%) cases, respectively. Treatment morbidity was 11.9%, without significant differences between surgical (15.6%) and endovascular (9.3%) patients (P = .09). Recurrences from coil compaction were safely treated by re-embolization, whereas recurrences from aneurysmal regrowth may best be managed surgically when technically feasible.
Analysis of Nonmodifiable Risk Factors for Intracranial Aneurysm Rupture in a Large, Retrospective Cohort
Authors: Amenta Peter S. , Yadla Sanjay , Campbell Peter G. , Maltenfort Mitchell G. , Dey Saugat , Ghosh Sayantani , Ali Muhammad S. , Jallo Jack I. , Tjoumakaris Stavropoula I. , Gonzalez L. Fernando , Dumont Aaron S. , Rosenwasser Robert H. , Jabbour Pascal M.
Published: October 2011

Background:

The risk factors predictive of intracranial aneurysm rupture remain incompletely defined.

Objective:

To examine the association between various nonmodifiable risk factors and aneurysm rupture in a large cohort of patients evaluated at a single institution.

Methods:

A retrospective analysis of patients admitted to a cerebrovascular facility between January 2006 and 2010 with a primary diagnosis of cerebral aneurysm. Aneurysms were divided into 2 groups: unruptured or ruptured. The dome diameter, aspect ratio (AR), location, sidedness, neck morphology, and multiplicity were entered into a central database. A full model was constructed, and a systematic removal of the least significant variables was performed in a sequential fashion until only those variables reaching significance remained.

Results:

We identified 2347 patients harboring 5134 individual aneurysms, of which 34.90% were ruptured and 65.09% were unruptured. On admission, 25.89% of aneurysms with a dome diameter <10 mm and 58.33% of aneurysms with a dome >10 mm were ruptured (P < .001). Of aneurysms with an AR >1.6, 52.44% presented following a rupture (P < .001). The highest incidence of rupture (69.21%) was observed in aneurysms with an AR >1.6, dome diameter <10 mm, and a deviated neck. Deviated neck-type aneurysms had a significantly greater incidence of rupture than classical necktype aneurysms (P < .001).

Conclusion:

An AR >1.6, dome diameter >10 mm, a deviated neck, and right-sidedness are independently associated with aneurysm rupture.
ε-Aminocaproic Acid in Angiographically Negative Subarachnoid Hemorrhage Patients Is Safe: A Retrospective Review of 83 Consecutive Patients
Authors: Hui Ferdinand K. , Schuette Albert J. , Lieber Michael , Spiotta Alejandro M. , Moskowitz Shaye I. , Barrow Daniel L. , Cawley C. Michael
Published: October 2011

Background:

ε-Aminocaproic acid (EACA) has been used to reduce the rate of cerebral aneurysm rerupture before definitive treatment. In centers administering EACA to patients with a subarachnoid hemorrhage (SAH), patients eventually diagnosed with angiographically negative subarachnoid hemorrhage (ANSAH) may also initially receive EACA, perhaps placing them at increased risk for ischemic complications.

Objective:

To evaluate the effect of short-term EACA on outcomes and secondary measures in patients with ANSAH.

Methods:

We conducted a retrospective study of 454 consecutive SAH patients over a 2-year period under a current protocol for EACA use. Patients were excluded if a source for the SAH was discovered, yielding a total of 83 ANSAH patients. The patients were assigned to groups that did or did not receive EACA. The primary end points of the study were ischemic complications, pulmonary emboli, vasospasm, ventriculoperitoneal shunting rates, and outcomes.

Results:

Statistical analysis yielded no significant difference between the 2 arms with respect to any of the end points: vasospasm (P = .65), deep vein thrombosis (P = .51), pulmonary embolism (P = 1.0), stroke (P = 1.0), myocardial infarction (P = 1.0), and ventriculoperitoneal shunt (P = .57). There was no statistically significant outcome difference using the modified Rankin Scale (P = .30).

Conclusion:

Short-term (<72 hour) application of EACA does not result in an increase in adverse events in patients with ANSAH.
Multiparametric analysis of magnetic resonance images for glioma grading and patient survival time prediction
Authors: Garzón Benjamín , Emblem Kyrre E , Mouridsen Kim , Nedregaard Baard , Due-Tønnessen Paulina , Nome Terje , Hald John K , Bjørnerud Atle , Håberg Asta K , Kvinnsland Yngve
Published: October 2011

Background

A systematic comparison of magnetic resonance imaging (MRI) options for glioma diagnosis is lacking.

Purpose

To investigate multiple MR-derived image features with respect to diagnostic accuracy in tumor grading and survival prediction in glioma patients.

Material and Methods

T1 pre- and post-contrast, T2 and dynamic susceptibility contrast scans of 74 glioma patients with histologically confirmed grade were acquired. For each patient, a set of statistical features was obtained from the parametric maps derived from the original images, in a region-of-interest encompassing the tumor volume. A forward stepwise selection procedure was used to find the best combinations of features for grade prediction with a cross-validated logistic model and survival time prediction with a cox proportional-hazards regression.

Results

Presence/absence of enhancement paired with kurtosis of the FM (first moment of the first-pass curve) was the feature combination that best predicted tumor grade (grade II vs. grade III-IV; median AUC = 0.96), with the main contribution being due to the first of the features. A lower predictive value (median AUC = 0.82) was obtained when grade IV tumors were excluded. Presence/absence of enhancement alone was the best predictor for survival time, and the regression was significant ( P < 0.0001).

Conclusion

Presence/absence of enhancement, reflecting transendothelial leakage, was the feature with highest predictive value for grade and survival time in glioma patients.
Diagnosis of lymph node metastasis in uterine cervical cancer: usefulness of computer-aided diagnosis with comprehensive evaluation of MR images and clinical findings
Authors: Kim Mi-hyun , Kim Jeong Kon , Lee Youngjoo , Park Bum-Woo , Lee Chang Kyung , Kim Namkug , Cho Gyunggoo , Choi Hyuck Jae , Cho Kyoung-Sik
Published: October 2011

Background

Lymph node (LN) status is an important parameter for determining the treatment strategy and for predicting the prognosis for patients with uterine cervical cancer. Computer-aided diagnosis (CAD) can be feasible for differentiating metastatic from non-metastatic lymph nodes in patients with uterine cervical cancer

Purpose

To determine the usefulness of CAD that comprehensively evaluates MR images and clinical findings for detecting LN metastasis in uterine cervical cancer.

Material and Methods

In 680 LNs from 143 patients who underwent radical hysterectomy for uterine cervical cancer, the CAD system using the Bayesian classifier estimated the probability of metastasis based on MR findings and clinical findings. We compared the diagnostic accuracy for detecting metastatic LNs in the CAD and MR findings.

Results

Metastasis was diagnosed in 70 (12%) LNs from 34 (24%) patients. The area under ROC curves of CAD (0.924) was greater than those of the mean ADC (0.854), minimum ADC (0.849), maximum ADC (0.827), short-axis diameter (0.856) and long-axis diameter (0.753) ( P < 0.05). The specificity and accuracy of the CAD (86%, 86%) were greater than those of the mean ADC (77%, 77%), maximum ADC (77%, 77%), minimum ADC (68%, 70%), and short-axis diameter (65%, 67%) ( P < 0.05).

Conclusion

CAD system can improve the diagnostic performance of MR for detecting metastatic LNs in uterine cervical cancer.
Competition in the NHS: A Provider Perspective
Authors: Frosini Francesca , Dixon Anna , Robertson1 Ruth
Published: October 2011

Objective

To analyse how competition is experienced and characterized by NHS and independent sector acute care providers in the English National Health Service (NHS).

Methods

Semi-structured interviews with 49 senior staff in 15 NHS trusts and independent sector providers between November 2008 and April 2009, in England.

Results

The market was predominantly defined based on geographical proximity. Competition was mainly on the periphery of catchment areas but markets were differentiated based on the scope and type of services. Niche providers, specialist hospitals and tertiary centres did not directly compete with district general hospital-type providers. Competitors were increasingly primary and community care providers, while there was little perceived threat from the private sector. There were many examples of how different providers (both NHS and independent sector) were co-operating and collaborating. Patients and general practitioners (GPs) appeared to be loyal to local providers.

Conclusion

The providers' view of the market and the relevance of historical relationships and loyalties suggest fine grained variations in competition which is consistent with a relational rather than structural approach to competition. Also the evidence on embeddedness of relationships implies that collaboration might be a strong lever for quality improvement locally. Finally, some of the agreements found might be deemed in breach of the rules of competition but they may well be in the interests of patients and taxpayers, with implications for regulation in publicly funded health care systems.
‘Animateurs’ and Animation: What Makes a Good Commissioning Manager?
Authors: Checkland Kath , Snow Stephanie , McDermott Imelda , Harrison Stephen , Coleman Anna
Published: October 2011

Objectives

To examine the managerial behaviours adopted by commissioning managers in English primary care trusts (PCTs), and to explore the impact of these behaviours.

Methods

Qualitative case studies were undertaken in four PCTs, focusing on staff engaged in the commissioning of hospital services. Both formal and informal observation were undertaken (150 hours), and 41 in-depth interviews conducted with managers and general practitioners (GPs).

Results

Managers adopted many managerial behaviours familiar from the literature, including sharing information, and networking inside and outside the organization. Multiple organizational layers and unclear decisionmaking processes hindered this activity. In addition, some managers with responsibility for facilitating practice-based commissioning (PbC) adopted a managerial mode that we have called being an ‘animateur’. This approach involved the active management of disparate groups of people over whom the manager had no authority, and appeared to be a factor in determining success. It was facilitated by managerial autonomy and was more prevalent where managers were seen to have legitimacy. Some organizational practices appeared to inhibit its development.

Conclusions

From 2012/13 it is planned that GPs will be taking more responsibility for commissioning in the English NHS. This research suggests that managers of the new commissioning organizations will require a deep and contextualized understanding of the NHS and that it is important that organizational processes do not inhibit managerial behaviour. Legitimacy may be an issue in contexts were managers are automatically transferred from their existing appointments.
Prenatal Diagnosis of the Wolf-Hirschhorn Syndrome with Increased Nuchal Translucency and Negative Serum Integrated Screening for Trisomy 21
Authors: Witters Ingrid , Gyselaers Wilfried , Mesens Tine , Wirjosoekarto Soetinah , Willekes Christine , Coumans Audrey , Viaene Paul , Fryns Jean-Pierre
Published: October 2011

The Wolf-Hirschhorn syndrome (WHS) is a contiguous gene deletion syndrome associated with a hemizygous deletion of chromosome 4p16.3. It is characterized by pre- and postnatal growth restriction, microcephaly, profound learning disability and seizure disorder, a ‘Greek helmet’ facies, and closure defects (cleft lip or palate, coloboma of the eye and cardiac septal defects). Prenatal diagnosis of the WHS (deletion 4p syndrome) has been established after karyotyping mainly for intrauterine growth restriction often with hypospadias, facial clefting and diaphragmatic hernia. Here we report the prenatal diagnosis of WHS at 19 weeks with increased nuchal translucency at 12 weeks, but a favourable integrated screening test due to low levels of B-human chorionic gonadotrophin (hCG). Low levels of hCG have been previously reported in Wolf-Hirschhorn syndrome.
Impaired branched chain amino acid metabolism alters feeding behavior and increases orexigenic neuropeptide expression in the hypothalamus
Authors: Purpera Megan N , Shen Li , Taghavi Marzieh , Münzberg Heike , Martin Roy J , Hutson Susan M , Morrison Christopher D
Published: October 2011

Elevation of dietary or brain leucine appears to suppress food intake via a mechanism involving mechanistic target of rapamycin, AMPK, and/or branched chain amino acid (BCAA) metabolism. Mice bearing a deletion of mitochondrial branched chain aminotransferase (BCATm), which is expressed in peripheral tissues (muscle) and brain glia, exhibit marked increases in circulating BCAAs. Here, we test whether this increase alters feeding behavior and brain neuropeptide expression. Circulating and brain levels of BCAAs were increased two- to four-fold in BCATm-deficient mice (KO). KO mice weighed less than controls (25.9 vs 20.4 g,P<0.01), but absolute food intake was relatively unchanged. In contrast to wild-type mice, KO mice preferred a low-BCAA diet to a control diet (P<0.05) but exhibited no change in preference for low- vs high-protein (HP) diets. KO mice also exhibited low leptin levels and increased hypothalamicNpyandAgrpmRNA. Normalization of circulating leptin levels had no effect on either food preference or the increasedNpyandAgrpmRNA expression. If BCAAs act as signals of protein status, one would expect reduced food intake, avoidance of dietary protein, and reduction in neuropeptide expression in BCATm-KO mice. Instead, these mice exhibit an increased expression of orexigenic neuropeptides and an avoidance of BCAAs but not HP. These data thus suggest that either BCAAs do not act as physiological signals of protein status or the loss of BCAA metabolism within brain glia impairs the detection of protein balance.
Empirical Evaluation Reveals Best Fit of a Logistic Mutation Model for Human Y-Chromosomal Microsatellites
Authors: Jochens Arne , Caliebe Amke , Rösler Uwe , Krawczak Michael
Published: October 2011

The rate of microsatellite mutation is dependent upon both the allele length and the repeat motif, but the exact nature of this relationship is still unknown. We analyzed data on the inheritance of human Y-chromosomal microsatellites in father–son duos, taken from 24 published reports and comprising 15,285 directly observable meioses. At the six microsatellites analyzed (DYS19, DYS389I, DYS390, DYS391, DYS392, and DYS393), a total of 162 mutations were observed. For each locus, we employed a maximum-likelihood approach to evaluate one of several single-step mutation models on the basis of the data. For five of the six loci considered, a novel logistic mutation model was found to provide the best fit according to Akaike’s information criterion. This implies that the mutation probability at the loci increases (nonlinearly) with allele length at a rate that differs between upward and downward mutations. For DYS392, the best fit was provided by a linear model in which upward and downward mutation probabilities increase equally with allele length. This is the first study to empirically compare different microsatellite mutation models in a locus-specific fashion.
A General Mechanistic Model for Admixture Histories of Hybrid Populations
Authors: Verdu Paul , Rosenberg Noah A
Published: October 2011

Admixed populations have been used for inferring migrations, detecting natural selection, and finding disease genes. These applications often use a simple statistical model of admixture rather than a modeling perspective that incorporates a more realistic history of the admixture process. Here, we develop a general model of admixture that mechanistically accounts for complex historical admixture processes. We consider two source populations contributing to the ancestry of a hybrid population, potentially with variable contributions across generations. For a random individual in the hybrid population at a given point in time, we study the fraction of genetic admixture originating from a specific one of the source populations by computing its moments as functions of time and of introgression parameters. We show that very different admixture processes can produce identical mean admixture proportions, but that such processes produce different values for the variance of the admixture proportion. When introgression parameters from each source population are constant over time, the long-term limit of the expectation of the admixture proportion depends only on the ratio of the introgression parameters. The variance of admixture decreases quickly over time after the source populations stop contributing to the hybrid population, but remains substantial when the contributions are ongoing. Our approach will facilitate the understanding of admixture mechanisms, illustrating how the moments of the distribution of admixture proportions can be informative about the historical admixture processes contributing to the genetic diversity of hybrid populations.
Sperm Status Regulates Sexual Attraction in Caenorhabditis elegans
Authors: Morsci Natalia S , Haas Leonard A , Barr Maureen M
Published: October 2011

Mating behavior of animals is regulated by the sensory stimuli provided by the other sex. Sexually receptive females emit mating signals that can be inhibited by male ejaculate. The genetic mechanisms controlling the release of mating signals and encoding behavioral responses remain enigmatic. Here we present evidence of a Caenorhabditis elegans hermaphrodite-derived cue that stimulates male mating-response behavior and is dynamically regulated by her reproductive status. Wild-type males preferentially mated with older hermaphrodites. Increased sex appeal of older hermaphrodites was potent enough to stimulate robust response from mating-deficient pkd-2 and lov-1 polycystin mutant males. This enhanced response of pkd-2 males toward older hermaphrodites was independent of short-chain ascaroside pheromones, but was contingent on the absence of active sperm in the hermaphrodites. The improved pkd-2 male response toward spermless hermaphrodites was blocked by prior insemination or by genetic ablation of the ceh-18-dependent sperm-sensing pathway of the hermaphrodite somatic gonad. Our work suggests an interaction between sperm and the soma that has a negative but reversible effect on a hermaphrodite-derived mating cue that regulates male mating response, a phenomenon to date attributed to gonochoristic species only.