bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rheumatoid arthritis mimicking metastatic squamous cell carcinoma
Authors: Gomez-Rivera Fernando , El-Naggar Adel K , Guha-Thakurta Nandita , Kupferman Michael E 
Published: May 2011

Abstract
We report a case of a cervical rheumatoid nodule in close relation to the hyoid bone mimicking a metastatic carcinoma. A 74-year-old female with a 15-year history of rheumatoid arthritis (RA) on treatment with methotrexate presented with tenderness of the right base of tongue. Imaging demonstrated a 1.4 cm cystic lesion at the hyoid bone. Biopsies were unsuccessful and the patient required surgical resection of the mass. A trans-cervical approach was used. Pathology revealed a necrotizing granuloma compatible with rheumatoid etiology. The clinician should be aware that, in a patient with a neck mass, in the presence of active RA, rheumatoid nodules should be part of the differential diagnosis.
Impact of Awareness of Terminal Illness and Use of Palliative Care or Intensive Care Unit on the Survival of Terminally Ill Patients With Cancer: Prospective Cohort Study
Authors: Yun Young Ho , Lee Myung Kyung , Kim Seon Young , Lee Woo Jin , Jung Kyung Hae , Do Young Rok , Kim Samyong , Heo Dae Seog , Choi Jong Soo , Park Sang Yoon , Jeong Hyun Sik , Kang Jung Hun , Kim Si-Young , Ro Jungsil , Lee Jung Lim , Park Sook Ryun , Park Sohee 
Published: May 2011

Purpose We conducted this study to evaluate the validity of the perception that awareness of their terminal prognosis and use of palliative care or nonuse of an intensive care unit (ICU) causes patients to die sooner than they would otherwise. Patients and Methods In this prospective cohort study at 11 university hospitals and the National Cancer Center in Korea, we administered questionnaires to 619 consecutive patients immediately after they were determined by physicians to be terminally ill. We followed patients during 6 months after enrollment and assessed how their survival was affected by the disclosure of terminal illness and administration of palliative care or nonuse of the ICU. Results In a follow-up of 481 patients and 163.8 person-years, we identified 466 deceased patients. Nineteen percent of the patients died within 1 month, while 41.3% lived for 3 months, and 17.7% lived for 6 months. Once the cancer was judged terminal, the median survival time was 69 days. On multivariate analysis, neither patient awareness of terminal status at baseline (adjusted hazard ratio [aHR], 1.20; 95% CI, 0.96 to 1.51), use of a palliative care facility (aHR, 0.96; 95% CI, 0.76 to 1.21), nor general prostration (aHR, 1.23; 95% CI, 0.96 to 1.57) was associated with reduced survival. Use of the ICU (aHR, 1.47; 95% CI, 1.06 to 2.05) and poor Eastern Cooperative Oncology Group performance status (aHR, 1.37; 95% CI, 1.10 to 1.71) were significantly associated with poor survival. Conclusion Patients' being aware that they are dying and entering a palliative care facility or ICU does not seem to influence patients' survival.
Loss of Nuclear Localized and Tyrosine Phosphorylated Stat5 in Breast Cancer Predicts Poor Clinical Outcome and Increased Risk of Antiestrogen Therapy Failure
Authors: Peck Amy R. , Witkiewicz Agnieszka K. , Liu Chengbao , Stringer Ginger A. , Klimowicz Alexander C. , Pequignot Edward , Freydin Boris , Tran Thai H. , Yang Ning , Rosenberg Anne L. , Hooke Jeffrey A. , Kovatich Albert J. , Nevalainen Marja T. , Shriver Craig D. , Hyslop Terry , Sauter Guido , Rimm David L. , Magliocco Anthony M. , Rui Hallgeir 
Published: May 2011

Purpose To investigate nuclear localized and tyrosine phosphorylated Stat5 (Nuc-pYStat5) as a marker of prognosis in node-negative breast cancer and as a predictor of response to antiestrogen therapy. Patients and Methods Levels of Nuc-pYStat5 were analyzed in five archival cohorts of breast cancer by traditional diaminobenzidine-chromogen immunostaining and pathologist scoring of whole tissue sections or by immunofluorescence and automated quantitative analysis (AQUA) of tissue microarrays. Results Nuc-pYStat5 was an independent prognostic marker as measured by cancer-specific survival (CSS) in patients with node-negative breast cancer who did not receive systemic adjuvant therapy, when adjusted for common pathology parameters in multivariate analyses both by standard chromogen detection with pathologist scoring of whole tissue sections (cohort I; n = 233) and quantitative immunofluorescence of a tissue microarray (cohort II; n = 291). Two distinct monoclonal antibodies gave concordant results. A progression array (cohort III; n = 180) revealed frequent loss of Nuc-pYStat5 in invasive carcinoma compared to normal breast epithelia or ductal carcinoma in situ, and general loss of Nuc-pYStat5 in lymph node metastases. In cohort IV (n = 221), loss of Nuc-pYStat5 was associated with increased risk of antiestrogen therapy failure as measured by univariate CSS and time to recurrence (TTR). More sensitive AQUA quantification of Nuc-pYStat5 in antiestrogen-treated patients (cohort V; n = 97) identified by multivariate analysis patients with low Nuc-pYStat5 at elevated risk for therapy failure (CSS hazard ratio [HR], 21.55; 95% CI, 5.61 to 82.77; P < .001; TTR HR, 7.30; 95% CI, 2.34 to 22.78; P = .001). Conclusion Nuc-pYStat5 is an independent prognostic marker in node-negative breast cancer. If confirmed in prospective studies, Nuc-pYStat5 may become a useful predictive marker of response to adjuvant hormone therapy.
Characteristics and Outcomes of Breast Cancer in Women With and Without a History of Radiation for Hodgkin's Lymphoma: A Multi-Institutional, Matched Cohort Study
Authors: Elkin Elena B. , Klem Michelle L. , Gonzales Anne Marie , Ishill Nicole M. , Hodgson David , Ng Andrea K. , Marks Lawrence B. , Weidhaas Joanne , Freedman Gary M. , Miller Robert C. , Constine Louis S. , Myrehaug Sten , Yahalom Joachim 
Published: May 2011

Purpose To compare characteristics and outcomes of breast cancer in women with and without a history of radiation therapy (RT) for Hodgkin's lymphoma (HL). Patients and Methods Women with breast cancer diagnosed from 1980 to 2006 after RT for HL were identified from eight North American hospitals and were matched three-to-one with patients with sporadic breast cancer by age, race, and year of breast cancer diagnosis. Information on patient, tumor and treatment characteristics, and clinical outcomes was abstracted from medical records. Results A total of 253 patients with breast cancer with a history of RT for HL were matched with 741 patients with sporadic breast cancer. Median time from HL to breast cancer diagnosis was 18 years. Median age at breast cancer diagnosis was 42 years. Breast cancer after RT for HL was more likely to be detected by screening, was more likely to be diagnosed at an earlier stage, and was more likely to be bilateral at diagnosis. HL survivors had an increased risk of metachronous contralateral breast cancer (adjusted hazard ratio [HR], 4.3; 95% CI, 1.7 to 11.0) and death as a result of any cause (adjusted HR, 1.9; 95% CI, 1.1 to 3.3). Breast cancer–specific mortality was also elevated, but this difference was not statistically significant (adjusted HR, 1.6; 95% CI, 0.7 to 3.4). Conclusion In women with a history of RT for HL, breast cancer is diagnosed at an earlier stage, but these women are at greater risk for bilateral disease and are more likely to die as a result of causes other than breast cancer. Our findings support close follow-up for contralateral tumors in these patients and ongoing primary care to manage comorbid conditions.
Centralized vs. Decentralized Ambulance Diversion: A Network Perspective
Authors: Deo Sarang , Gurvich Itai 
Published: May 2011

One of the most important operational challenges faced by emergency departments (EDs) in the United States is patient overcrowding. In periods of overcrowding, an ED can request the emergency medical services (EMS) agency to divert incoming ambulances to neighboring hospitals, a phenomenon known as “ambulance diversion.” The EMS agency may accept this request provided that at least one of the neighboring EDs is not on diversion. From an operations perspective, properly executed ambulance diversion should result in resource pooling and reduce the overcrowding and delays in a network of EDs. Recent evidence indicates, however, that this potential benefit is not always realized. In this paper, we provide one potential explanation for this discrepancy and suggest potential remedies. Using a queueing game between two EDs that aim to minimize their own waiting time, we find that decentralized decisions regarding diversion explain the lack of pooling benefits. Specifically, we find the existence of a defensive equilibrium, wherein each ED does not accept diverted ambulances from the other ED. This defensiveness results in a depooling of the network and, subsequently, in delays that are significantly higher than when a social planner coordinates diversion. The social optimum is itself difficult to characterize analytically and has limited practical appeal because it depends on problem parameters such as arrival rates and length of stay. Instead, we identify an alternative solution that does not require the exact knowledge of the parameters and may be used by the EMS agencies to coordinate diversion decisions when defensive diversion is present. We show that this solution is approximately optimal for the social planner's problem. Moreover, it is Pareto improving over the defensive equilibrium whereas the social optimum, in general, might not be. This paper was accepted by Yossi Aviv, operations management.
Modeling the Loss Distribution
Authors: Chava Sudheer , Stefanescu Catalina , Turnbull Stuart 
Published: May 2011

In this paper, we focus on modeling and predicting the loss distribution for credit risky assets such as bonds and loans. We model the probability of default and the recovery rate given default based on shared covariates. We develop a new class of default models that explicitly accounts for sector specific and regime dependent unobservable heterogeneity in firm characteristics. Based on the analysis of a large default and recovery data set over the horizon 1980–2008, we document that the specification of the default model has a major impact on the predicted loss distribution, whereas the specification of the recovery model is less important. In particular, we find evidence that industry factors and regime dynamics affect the performance of default models, implying that the appropriate choice of default models for loss prediction will depend on the credit cycle and on portfolio characteristics. Finally, we show that default probabilities and recovery rates predicted out of sample are negatively correlated and that the magnitude of the correlation varies with seniority class, industry, and credit cycle. This paper was accepted by Wei Xiong, finance.
Market Timing with Option-Implied Distributions: A Forward-Looking Approach
Authors: Kostakis Alexandros , Panigirtzoglou Nikolaos , Skiadopoulos George 
Published: May 2011

We address the empirical implementation of the static asset allocation problem by developing a forward-looking approach that uses information from market option prices. To this end, we extract constant maturity S&P 500 implied distributions and transform them to the corresponding risk-adjusted ones. Then we form optimal portfolios consisting of a risky and a risk-free asset and evaluate their out-of-sample performance. We find that the use of risk-adjusted implied distributions times the market and makes the investor better off than if she uses historical returns' distributions to calculate her optimal strategy. The results hold under a number of evaluation metrics and utility functions and carry through even when transaction costs are taken into account. Not surprisingly, the reported market timing ability deteriorated during the recent subprime crisis. An extension of the approach to a dynamic asset allocation setting is also presented. This paper was accepted by Wei Xiong, finance.
Low-energy shock waves enhance the susceptibility of staphylococcal biofilms to antimicrobial agents in vitro
Authors: Wanner S. , Gstöttner M. , Meirer R. , Hausdorfer J. , Fille M. , Stöckl B. 
Published: May 2011

Biofilm-associated infections in wounds or on implants are difficult to treat. Eradication of the bacteria is nearly always impossible, despite the use of specific antibiotics. The bactericidal effects of high-energy extracorporeal shock waves on Staphylococcus aureus have been reported, but the effect of low-energy shock waves on staphylococci and staphylococcal biofilms has not been investigated. In this study, biofilms grown on stainless steel washers were examined by electron microscopy. We tested ten experimental groups with Staph. aureus-coated washers and eight groups with Staph. epidermidis. The biofilm-cultured washers were exposed to low-energy shock waves at 0.16 mJ/mm2 for 500 impulses. The washers were then treated with cefuroxime, rifampicin and fosfomycin, both alone and in combination. All tests were carried out in triplicate. Viable cells were counted to determine the bactericidal effect. The control groups of Staph. aureus and Staph. epidermidis revealed a cell count of 6 × 108 colony-forming units/ml. Complete eradication was achieved using the combination of antibiotic therapy (single antibiotic in Staph. aureus, a combination in Staph. epidermidis) and shock wave application (p < 0.01). We conclude that shock waves combined with antibiotics could be tested in an in vitro model of infection.
The influence of socioeconomic status on the incidence, outcome and mortality of fractures of the hip
Authors: Quah C. , Boulton C. , Moran C. 
Published: May 2011

This is the first study to use the English Indices of Multiple Deprivation 2007, the Government’s official measure of multiple deprivation, to analyse the effect of socioeconomic status on the incidence of fractures of the hip and their outcome and mortality. Our sample consisted of all patients admitted to hospital with a fracture of the hip (n = 7511) in Nottingham between 1999 and 2009. The incidence was 1.3 times higher (p = 0.038) in the most deprived populations than in the least deprived; the most deprived suffered a fracture, on average, 1.1 years earlier (82.0 years versus 83.1 years, p < 0.001). The mortality rate proved to be significantly higher in the most deprived population (log-rank test, p = 0.033), who also had a higher number of comorbidities (p = 0.001). This study has shown an increase in the incidence of fracture of the hip in the most deprived population, but no association between socioeconomic status and mortality at 30 days. Preventative programmes aimed at reducing the risk of hip fracture should be targeted towards the more deprived if they are to make a substantial impact.
Human hip impingement morphology
Authors: Hogervorst T. , Bouma H. , de Boer S. F. , de Vos J. 
Published: May 2011

We examined the morphology of mammalian hips asking whether evolution can explain the morphology of impingement in human hips. We describe two stereotypical mammalian hips, coxa recta and coxa rotunda. Coxa recta is characterised by a straight or aspherical section on the femoral head or head-neck junction. It is a sturdy hip seen mostly in runners and jumpers. Coxa rotunda has a round femoral head with ample head-neck offset, and is seen mostly in climbers and swimmers. Hominid evolution offers an explanation for the variants in hip morphology associated with impingement. The evolutionary conflict between upright gait and the birth of a large-brained fetus is expressed in the female pelvis and hip, and can explain pincer impingement in a coxa profunda. In the male hip, evolution can explain cam impingement in coxa recta as an adaptation for running.
Complications and outcome of tibial lengthening using the Ilizarov method with or without a supplementary intramedullary nail
Authors: Sun X.-T. , Easwar T. R. , Manesh S. , Ryu J.-H. , Song S.-H. , Kim S.-J. , Song H.-R. 
Published: May 2011

We compared the complications and outcome of tibial lengthening using the Ilizarov method with and without the use of a supplementary intramedullary nail. In a retrospective case-matched series assembled from 176 patients with tibial lengthening, we matched 52 patients (26 pairs, group A with nail and group B without) according to the following criteria in order of importance: 1) difference in amount of lengthening (± 2 cm); 2) percentage difference in lengthening (± 5%); 3) difference in patient’s age (± seven years); 4) aetiology of the shortening, and 5) level of difficulty in obtaining the correction. The outcome was evaluated using the external fixator index, the healing index and an outcome score according to the criteria of Paley. It was found that some complications were specific to group A or B respectively, but others were common to both groups. The outcome was generally better in lengthenings with a nail, although there was a higher incidence of rectifiable equinus deformity in these patients.
An analysis of metal ion levels in the joint fluid of symptomatic patients with metal-on-metal hip replacements
Authors: Davda K. , Lali F. V. , Sampson B. , Skinner J. A. , Hart A. J. 
Published: May 2011

We retrospectively analysed concentrations of chromium and cobalt ions in samples of synovial fluid and whole blood taken from a group of 92 patients with failed current-generation metal-on-metal hip replacements. We applied acid oxidative digestion to our trace metal analysis protocol, which found significantly higher levels of metal ion concentrations in blood and synovial fluid than a non-digestive method. Patients were subcategorised by mode of failure as either ‘unexplained pain’ or ‘defined causes’. Using this classification, chromium and cobalt ion levels were present over a wider range in synovial fluid and not as strongly correlated with blood ion levels as previously reported. There was no significant difference between metal ion concentrations and manufacturer of the implant, nor femoral head size below or above 50 mm. There was a moderately positive correlation between metal ion levels and acetabular component inclination angle as measured on three-dimensional CT imaging. Our results suggest that acid digestion of samples of synovial fluid samples is necessary to determine metal ion concentrations accurately so that meaningful comparisons can be made between studies.
Adolescent slipped capital femoral epiphysis treated by a modified Dunn osteotomy with surgical hip dislocation
Authors: Huber H. , Dora C. , Ramseier L. E. , Buck F. , Dierauer S. 
Published: May 2011

Between June 2001 and November 2008 a modified Dunn osteotomy with a surgical hip dislocation was performed in 30 hips in 28 patients with slipped capital femoral epiphysis. Complications and clinical and radiological outcomes after a mean follow-up of 3.8 years (1.0 to 8.5) were documented. Subjective outcome was assessed using the Harris hip score and the Western Ontario and McMaster Universities osteoarthritis index questionnaire. Anatomical or near-anatomical reduction was achieved in all cases. The epiphysis in one hip showed no perfusion intra-operatively and developed avascular necrosis. There was an excellent outcome in 28 hips. Failure of the implants with a need for revision surgery occurred in four hips. Anatomical reduction can be achieved by this technique, with a low risk of avascular necrosis. Cautious follow-up is necessary in order to avoid implant failure.
First-time revision using impacted morsellised allograft bone with a cemented Exeter stem
Authors: Zampelis V. , Ornstein E. , Franzén H. , Atroshi I. 
Published: May 2011

Previously, radiostereometric analysis following hip revision performed using impacted morsellised allograft bone and a cemented Exeter stem has shown continuous subsidence of the stem for up to five years. It is not known whether the subsidence continues thereafter. In our study, 17 of 25 consecutive osteo-arthritic patients with aseptically loose stems who underwent first-time revision using impacted morsellised allograft bone and a cemented Exeter stem were followed by yearly radiostereometric examinations for nine years. The mean subsidence at six weeks was 1.1 mm (0.1 to 2.3), from six weeks to one year 1.3 mm (0 to 2.6), from one to five years 0.7 mm (0 to 2.0), and from five to nine years 0.7 mm (0.1 to 3.1). That from six weeks to nine years was 2.7 mm (0 to 6.4) (95% confidence interval 2.0 to 3.5). The Charnley pain score significantly improved after revision, and was maintained at nine years, but walking ability deteriorated slightly as follow-up extended. Of the eight patients who were not followed for nine years, two had early subsidence exceeding 11 mm. Our findings show that in osteo-arthritic patients who undergo revision for aseptic loosening of the stem using impacted morsellised allograft bone and a cemented Exeter stem, migration of the stem continues over nine years at a slower rate after the first year, but without clinical deterioration or radiological loosening.
Assessment of radiolucent lines around the Oxford unicompartmental knee replacement
Authors: Kalra S. , Smith T. O. , Berko B. , Walton N. P. 
Published: May 2011

The Oxford unicompartmental knee replacement gives good results in patients with symptomatic osteoarthritis of the medial compartment. Previous studies have suggested that the presence of radiolucent lines (RLLs) does not reflect a poor outcome in such patients. However, the reliability and validity of this assessment have not been determined. Our aim was to assess the intra- and interobserver reliability and the sensitivity and specificity of the assessment of RLLs around both tibial and femoral components using standard radiographs. Two reviewers assessed the radiographs of 45 patients who had loosening of the tibial or femoral component confirmed at revision surgery and compared them with those of a series of 45 asymptomatic patients matched for age and gender. The results suggested that, using standard radiographs, tibial RLLs were 63.6% sensitive and 94.4% specific and femoral RLLs 63.9% sensitive and 72.7% specific for loosening. Overall intra- and interobserver reliability was highly variable, but zonal analysis showed that lucency at the tip of the femoral peg was significantly associated with loosening of the femoral component. Fluoroscopically guided radiographs may improve the zonal reliability of the assessment of RLLs, but further independent and comparative studies are required. In the meantime, the innocence of the physiological RLLs detected by standard radiographs should be viewed with caution.
Fixation of intracapsular fractures of the femoral neck in young patients
Authors: Duckworth A. D. , Bennet S. J. , Aderinto J. , Keating J. F. 
Published: May 2011

The aim of this study was to determine the comorbid risk factors for failure in young patients who undergo fixation of a displaced fracture of the femoral neck. We identified from a prospective database all such patients ≤ 60 years of age treated with reduction and internal fixation. The main outcome measures were union, failure of fixation, nonunion and the development of avascular necrosis.There were 122 patients in the study. Union occurred in 83 patients (68%) at a mean follow-up of 58 months (18 to 155). Complications occurred in 39 patients (32%) at a mean of 11 months (0.5 to 39). The rate of nonunion was 7.4% (n = 9) and of avascular necrosis was 11.5% (n = 14). Failures were more common in patients over 40 years of age (p = 0.03). Univariate analysis identified that delay in time to fixation (> 24 hours), alcohol excess and pre-existing renal, liver or respiratory disease were all predictive of failure (all p < 0.05). Of these, alcohol excess, renal disease and respiratory disease were most predictive of failure on multivariate analysis.Younger patients with fractures of the femoral neck should be carefully evaluated for comorbidities that increase the risk of failure after reduction and fixation. In patients with a history of alcohol abuse, renal or respiratory disease, arthroplasty should be considered as an alternative treatment.