1,459 research outputs found
Endobronchial Carcinoid Tumour with Extensive Ossification: An Unusual Case Presentation
Carcinoid tumour is a well-known primary endobronchial lung neoplasm. Although calcifications may be seen in up to 30% of pulmonary carcinoid tumours, near complete ossification of these tumours is an unusual finding. Such lesions can prove diagnostically challenging at the time of intraoperative frozen section as the latter technique requires thin sectioning of the lesion for microscopic assessment. We present an unusual case of endobronchial carcinoid tumour with extensive ossification in a 45-year-old male. Preliminary intraoperative diagnosis was achieved through the alternative use of cytology scrape smears. The final diagnosis was confirmed after decalcification of the tumour. The prognostic implications of heavily ossified carcinoid tumours remain elusive. Long-term clinical follow-up of these patients is recommended
Comparison of Operative Mortality and Complications between Bronchoplastic Lobectomy and Pneumonectomy in Lung Cancer Patients
Bronchoplastic lobectomy is a lung-saving procedure indicated for central tumors, for which the alternative is pneumonectomy. We compared operative mortality and complications between bronchoplastic lobectomy and pneumonectomy in lung cancer patients. From March 1993 through December 2005, 1,461 patients were surgically resected for non-small cell lung cancer, including 73 who underwent bronchoplastic lobectomy and 258 who underwent pneumonectomy. Bronchoplastic lobectomy was performed on any lesion that could be completely resected by this technique, whereas pneumonectomy was only performed on lesions that could not be removed by bronchoplastic lobectomy. Operative deaths occurred in 1 of 73 (1.4%) bronchoplastic lobectomy and 26 of 258 (10.1%) pneumonectomy patients (p=0.014). Major complications occurred in 16 of 73 (21.9%) bronchoplastic lobectomy and 58 of 258 (22.5%) pneumonectomy patients (p=1.0). Bronchoplastic lobectomy has a lower risk of operative mortality than pneumonectomy. Although the complication rates were similar, bronchoplastic lobectomy was associated with improved postoperative cardiopulmonary status and a low prevalence of fatal complications after bronchial anastomosis. These findings indicate that bronchoplastic lobectomy is a valuable alternative to pneumonectomy for anatomically appropriate patients, regardless of underlying cardiopulmonary function
Determining Risk of Falls in Community-Dwelling Older Adults: A Systematic Review and Meta-analysis Using Posttest Probability
BACKGROUND:
Falls and their consequences are significant concerns for older adults, caregivers, and health care providers. Identification of fall risk is crucial for appropriate referral to preventive interventions. Falls are multifactorial; no single measure is an accurate diagnostic tool. There is limited information on which history question, self-report measure, or performance-based measure, or combination of measures, best predicts future falls.
PURPOSE:
First, to evaluate the predictive ability of history questions, self-report measures, and performance-based measures for assessing fall risk of community-dwelling older adults by calculating and comparing posttest probability (PoTP) values for individual test/measures. Second, to evaluate usefulness of cumulative PoTP for measures in combination.
DATA SOURCES:
To be included, a study must have used fall status as an outcome or classification variable, have a sample size of at least 30 ambulatory community-living older adults (≥65 years), and track falls occurrence for a minimum of 6 months. Studies in acute or long-term care settings, as well as those including participants with significant cognitive or neuromuscular conditions related to increased fall risk, were excluded. Searches of Medline/PubMED and Cumulative Index of Nursing and Allied Health (CINAHL) from January 1990 through September 2013 identified 2294 abstracts concerned with fall risk assessment in community-dwelling older adults.
STUDY SELECTION:
Because the number of prospective studies of fall risk assessment was limited, retrospective studies that classified participants (faller/nonfallers) were also included. Ninety-five full-text articles met inclusion criteria; 59 contained necessary data for calculation of PoTP. The Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS) was used to assess each study\u27s methodological quality.
DATA EXTRACTION:
Study design and QUADAS score determined the level of evidence. Data for calculation of sensitivity (Sn), specificity (Sp), likelihood ratios (LR), and PoTP values were available for 21 of 46 measures used as search terms. An additional 73 history questions, self-report measures, and performance-based measures were used in included articles; PoTP values could be calculated for 35.
DATA SYNTHESIS:
Evidence tables including PoTP values were constructed for 15 history questions, 15 self-report measures, and 26 performance-based measures. Recommendations for clinical practice were based on consensus.
LIMITATIONS:
Variations in study quality, procedures, and statistical analyses challenged data extraction, interpretation, and synthesis. There was insufficient data for calculation of PoTP values for 63 of 119 tests.
CONCLUSIONS:
No single test/measure demonstrated strong PoTP values. Five history questions, 2 self-report measures, and 5 performance-based measures may have clinical usefulness in assessing risk of falling on the basis of cumulative PoTP. Berg Balance Scale score (≤50 points), Timed Up and Go times (≥12 seconds), and 5 times sit-to-stand times (≥12) seconds are currently the most evidence-supported functional measures to determine individual risk of future falls. Shortfalls identified during review will direct researchers to address knowledge gaps
Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV
The t t-bar production cross section (sigma[t t-bar]) is measured in
proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS
experiment, corresponding to an integrated luminosity of 2.3 inverse
femtobarns. The measurement is performed in events with two leptons (electrons
or muons) in the final state, at least two jets identified as jets originating
from b quarks, and the presence of an imbalance in transverse momentum. The
measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/-
2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction
of the standard model.Comment: Replaced with published version. Included journal reference and DO
Search for anomalous t t-bar production in the highly-boosted all-hadronic final state
A search is presented for a massive particle, generically referred to as a
Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are
sufficiently massive to produce highly Lorentz-boosted top quarks, which yield
collimated decay products that are partially or fully merged into single jets.
The analysis uses new methods to analyze jet substructure, providing
suppression of the non-top multijet backgrounds. The analysis is based on a
data sample of proton-proton collisions at a center-of-mass energy of 7 TeV,
corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits
in the range of 1 pb are set on the product of the production cross section and
branching fraction for a topcolor Z' modeled for several widths, as well as for
a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any
enhancement in t t-bar production beyond expectations of the standard model for
t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version
includes a minor typo correction that will be submitted as an erratu
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