LLukas22/scidocs huggingface dataset:
Computed tomographic pulmonary angiography vs ventilation-perfusion lung scanning in patients with suspected pulmonary embolism: a randomized controlled trial.

CONTEXT
Ventilation-perfusion (V(dot)Q(dot) lung scanning and computed tomographic pulmonary angiography (CTPA) are widely used imaging procedures for the evaluation of patients with suspected pulmonary embolism. Ventilation-perfusion scanning has been largely replaced by CTPA in many centers despite limited comparative formal evaluations and concerns about CTPA's low sensitivity (ie, chance of missing clinically important pulmonary embuli).


OBJECTIVES
To determine whether CTPA may be relied upon as a safe alternative to V(dot)Q(dot scanning as the initial pulmonary imaging procedure for excluding the diagnosis of pulmonary embolism in acutely symptomatic patients.


DESIGN, SETTING, AND PARTICIPANTS
Randomized, single-blinded noninferiority clinical trial performed at 4 Canadian and 1 US tertiary care centers between May 2001 and April 2005 and involving 1417 patients considered likely to have acute pulmonary embolism based on a Wells clinical model score of 4.5 or greater or a positive D-dimer assay result.


INTERVENTION
Patients were randomized to undergo either V(dot)Q(dot scanning or CTPA. Patients in whom pulmonary embolism was considered excluded did not receive antithrombotic therapy and were followed up for a 3-month period.


MAIN OUTCOME MEASURE
The primary outcome was the subsequent development of symptomatic pulmonary embolism or proximal deep vein thrombosis in patients in whom pulmonary embolism had initially been excluded.


RESULTS
Seven hundred one patients were randomized to CTPA and 716 to V(dot)Q(dot scanning. Of these, 133 patients (19.2%) in the CTPA group vs 101 (14.2%) in the V(dot)Q(dot scan group were diagnosed as having pulmonary embolism in the initial evaluation period (difference, 5.0%; 95% confidence interval [CI], 1.1% to 8.9%) and were treated with anticoagulant therapy. Of those in whom pulmonary embolism was considered excluded, 2 of 561 patients (0.4%) randomized to CTPA vs 6 of 611 patients (1.0%) undergoing V(dot)Q(dot scanning developed venous thromboembolism in follow-up (difference, -0.6%; 95% CI, -1.6% to 0.3%) including one patient with fatal pulmonary embolism in the V(dot)Q(dot group.


CONCLUSIONS
In this study, CTPA was not inferior to V(dot)Q(dot scanning in ruling out pulmonary embolism. However, significantly more patients were diagnosed with pulmonary embolism using the CTPA approach. Further research is required to determine whether all pulmonary emboli detected by CTPA should be managed with anticoagulant therapy.


TRIAL REGISTRATION
isrctn.org Identifier: ISRCTN65486961.
Resting-state networks distinguish locked-in from vegetative state patients☆

PURPOSE
Locked-in syndrome and vegetative state are distinct outcomes from coma. Despite their differences, they are clinically difficult to distinguish at the early stage and current diagnostic tools remain insufficient. Since some brain functions are preserved in locked-in syndrome, we postulated that networks of spontaneously co-activated brain areas might be present in locked-in patients, similar to healthy controls, but not in patients in a vegetative state.


METHODS
Five patients with locked-in syndrome, 12 patients in a vegetative state and 19 healthy controls underwent a resting-state fMRI scan. Individual spatial independent component analysis was used to separate spontaneous brain co-activations from noise. These co-activity maps were selected and then classified by two raters as either one of eight resting-state networks commonly shared across subjects or as specific to a subject.


RESULTS
The numbers of spontaneous co-activity maps, total resting-state networks, and resting-state networks underlying high-level cognitive activity were shown to differentiate controls and locked-in patients from patients in a vegetative state. Analyses of each common resting-state network revealed that the default mode network accurately distinguished locked-in from vegetative-state patients. The frontoparietal network also had maximum specificity but more limited sensitivity.


CONCLUSIONS
This study reinforces previous reports on the preservation of the default mode network in locked-in syndrome in contrast to vegetative state but extends them by suggesting that other networks might be relevant to the diagnosis of locked-in syndrome. The aforementioned analysis of fMRI brain activity at rest might be a step in the development of a diagnostic biomarker to distinguish locked-in syndrome from vegetative state.
Characterization of patients aged 45 or under admitted with hypertensive emergencies in the Hospital do Prenda.

INTRODUCTION AND OBJECTIVES
The incidence and prevalence of hypertensive emergency have been little addressed in the literature. However, over the last decade increasing numbers of young patients with different forms of hypertensive crisis have been observed in emergency departments. We performed this study to ascertain the clinical and epidemiological characteristics of patients aged ≤ 45 years admitted with a diagnosis of hypertensive emergency.


METHODS
We conducted an observational, descriptive, cross-sectional prospective study of 123 patients hospitalized for hypertensive emergency in the Hospital do Prenda, Luanda, between May 2011 and June 2012.


RESULTS
Mean age was 36.62 ± 5.49 years, and most were male (52.85%). The main risk factor was hypertension (65.9%), with 17.3% complying with therapy. The most frequent forms of presentation were hypertensive encephalopathy and hemorrhagic stroke (9.8% and 82.1%, respectively). The main drugs used were diuretics, angiotensin-converting enzyme inhibitors and calcium channel blockers. Mortality during hospitalization was 25.2% (31 patients), hemorrhagic stroke being the most common cause. There was a significant association between age and in-hospital mortality.


CONCLUSIONS
Of patients admitted with hypertensive emergency, 30.1% were aged ≤ 45 years. Hemorrhagic stroke was the most common presentation. There was a significant relationship between mode of presentation, age and in-hospital mortality.
Efficient Learning of Sparse Representations with an Energy-Based Model

We describe a novel unsupervised method for learning sparse, overcomplete features. The model uses a linear encoder, and a linear decoder preceded by a sparsifying non-linearity that turns a code vector into a quasi-binary sparse code vector. Given an input, the optimal code minimizes the distance between the output of the decoder and the input patch while being as similar as possible to the encoder output. Learning proceeds in a two-phase EM-like fashion: (1) compute the minimum-energy code vector, (2) adjust the parameters of the encoder and decoder so as to decrease the energy. The model produces “stroke detectors” when trained on handwritten numerals, and Gabor-like filters when trained on natural image patches. Inference and learning are very fast, requiring no preprocessing, and no expensive sampling. Using the proposed unsupervised method to initialize the first layer of a convolutional network, we achieved an error rate slightly lower than the best reported result on the MNIST dataset. Finally, an extension of the method is described to learn topographical filter maps.
MANAGING WITH STYLE : THE EFFECT OF MANAGERS ON FIRM POLICIES ∗

This paper investigates whether and how individual managers affect corporate behavior and performance. We construct a manager-firm matched panel data set which enables us to track the top managers across different firms over time. We find that manager fixed effects matter for a wide range of corporate decisions. A significant extent of the heterogeneity in investment, financial and organizational practices of firms can be explained by the presence of manager fixed effects. We identify specific patterns in managerial decision making that appear to indicate general differences in “style” across managers. Moreover, we show that management style is significantly related to manager fixed effects in performance and that managers with higher performance fixed effects receive higher compensation and are more likely to be found in better governed firms. In a final step, we tie back these findings to observable managerial characteristics. We find that executives from earlier birth cohorts appear on average to be more conservative; on the other hand, managers who hold an MBA degree seem to follow on average more aggressive strategies. ∗We thank the editors (Lawrence Katz and Edward Glaeser), three anonymous referees, Kent Daniel, Rebecca Henderson, Steven Kaplan, Kevin J. Murphy, Sendhil Mullainathan, Canice Prendergast, David Scharfstein, Jerry Warner, Michael Weisbach, seminar participants at Harvard University, the Kellogg Graduate School of Management, the Massachusetts Institute of Technology, the University of Chicago Graduate School of Business, the University of Illinois at Urbana-Champaign, Rochester University and the Stockholm School of Economics for many helpful comments. We thank Kevin J. Murphy and Robert Parrino for generously providing us with their data. Jennifer Fiumara and Mike McDonald provided excellent research assistance. E-mail: marianne.bertrand@gsb.uchicago.edu; aschoar@mit.edu.
Opposite regulation of XIAP and Smac/DIABLO in the rat endometrium in response to 17β-estradiol at estrus

During rat estrous cycle, the endometrium proliferates in response to sex steroids and specific endometrial epithelial cells undergo apoptosis in absence of embryonic factors. The central executioner of apoptosis is a family of aspartic acid-specific cysteine proteases known as caspases. Smac/DIABLO is released from the mitochondria during apoptosis and its stimulation promotes caspases activation by neutralizing members of the inhibitor of apoptosis proteins (IAPs) family, such as X-linked inhibitor of apoptosis protein (XIAP). The aim of this study was to investigate the involvement of Smac/DIABLO and XIAP in the control of caspases activation in endometrium of cycling rats. Polyoestrus female rats were sacrificed at each stage of estrous cycle (diestrus, proestrus, estrus, and metestrus). Endometrial protein extracts were collected to perform Western Blot analysis. Alternatively, uterine horns were sectioned for immunohistochemistry (IHC). We and others showed previously the presence of apoptosis at estrus in rat uterine epithelium. In the present study, cleaved caspase-3, -6, and -7 fragments were detected at estrus. IHC confirmed that caspase-3 was present only in luminal and glandular epithelium at estrus. XIAP was highly expressed at estrus in both epithelial and stromal cells. In contrast, expression of Smac/DIABLO was elevated at diestrus, proestrus and metestrus but was minimal at estrus. Treatment of ovariectomized rats with 17beta-estradiol induced XIAP expression and inhibited Smac/DIABLO protein expression in the endometrium. Cleaved caspase-3, -6, and -7 fragments increased in endometrial protein extracts following 17beta-estradiol treatment. Expression of NF-kappaB and IkappaB proteins, and IkappaB phosphorylation status were detected in the endometrium but were not influenced by the estrous cycle. These findings suggest that Smac/DIABLO and XIAP are regulated differently and may play important roles in the regulation of endometrial cell fate. Moreover, this study confirms a key role for executioner caspases in the control of apoptotic processes at estrus in the rat uterus.
Camera Self-Calibration in Underwater Environment

This paper presents a self-calibration technique for a camera mounted on an underwater vehicle designed to perform the 3D reconstruction of underwater scenes. Our aim is to identify the intrinsic parameters of the camera with methods that are adapted to the operational constraints on Ifremer’s underwater vehicles. The optical system is composed by a single vertical camera located below the underwater vehicle and looking downwards. The motion of the vehicle can be measured through navigation sensors and the observed 3D scene is always unknown. The use of a moving camera is not an obstacle for the application of stereoscopic methods. Nevertheless, the camera motion enables the use of robust algorithms for points matching, but impoverishes perspective effects between several images. Therefore, we are interested in the analysis of the conditions in which the procedure of self-calibration is valid and reliable, i.e.: the 3D characteristics of the scene and the camera motion. This paper presents the steps necessary for the camera self-calibration in an underwater environment: the extraction and the tracking of features in several successive images, the fundamental matrix estimation and the intrinsic parameters identification. Several tests and results are presented.
Negative chest X-rays in primary care patients with lung cancer.

BACKGROUND
The main investigation for suspected lung cancer in primary care is a chest X-ray. Reports from secondary care show that some patients with normal chest X-rays transpire to have lung cancer. The assumption is that this occurs rarely in primary care.


AIM
The aim of this study was to examine the frequency of misleading chest X-rays in primary care, and whether there were any particular symptoms associated with them.


DESIGN OF STUDY
Retrospective cohort study of the primary care records of 247 lung cancer patients diagnosed between 1998-2002.


SETTING
All general practices in Exeter Primary Care Trust, Devon, UK.


METHOD
All chest X-rays and all common symptoms of lung cancer reported to primary care were identified from the medical records. X-ray results were categorised into three groups by the radiologist's report: normal; abnormal but no malignancy suspected (together classified as negative X-rays); or abnormal with possible malignancy.


RESULTS
Of the 247 patients, 164 (66%) had a chest X-ray taken in primary care during the year before diagnosis: 126 of these (77%) were abnormal with possible malignancy; 21 (13%) were abnormal but with no malignancy suspected; in 17 (10%) the X-ray was reported as normal. Thus, 38 of 164 patients (23%; 95% confidence interval = 16 to 32%) had a negative X-ray. Negative X-rays were less common in the 90 days before diagnosis. No particular symptoms were significantly associated with negative X-rays.


CONCLUSION
Nearly a quarter of chest X-rays requested from primary care in lung cancer patients are negative. Further investigation is warranted with continuing or changing symptoms, even if the X-ray is not suggestive of malignancy.
Association of the response to tumor necrosis factor antagonists with plasma type I interferon activity and interferon-beta/alpha ratios in rheumatoid arthritis patients: a post hoc analysis of a predominantly Hispanic cohort.

OBJECTIVE
Despite the substantial clinical efficacy of tumor necrosis factor alpha (TNFalpha) antagonist therapy in patients with rheumatoid arthritis (RA), some patients respond poorly to such agents. Since an interferon (IFN) signature is variably expressed among RA patients, we investigated whether plasma type I IFN activity might predict the response to TNF antagonist therapy.


METHODS
RA patients (n = 35), the majority of whom were Hispanic, from a single center were evaluated before and after initiation of TNF antagonist therapy. As controls, 12 RA patients from the same center who were not treated with a TNF antagonist were studied. Plasma type I IFN activity was measured using a reporter cell assay, and disease status was assessed using the Disease Activity Score in 28 joints (DAS28). Levels of interleukin-1 receptor antagonist (IL-1Ra) were determined in baseline plasma samples using a commercial enzyme-linked immunosorbent assay. The clinical response was classified according to the European League Against Rheumatism criteria for improvement in RA.


RESULTS
Plasma type I IFN activity at baseline was significantly associated with clinical response (odds ratio 1.36 [95% confidence interval 1.05-1.76], P = 0.020), with high baseline IFN activity associated with a good response. Changes in DAS28 scores were greater among patients with a baseline plasma IFNbeta/alpha ratio >0.8 (indicating elevated plasma IFNbeta levels). Consistent with the capacity of IFNbeta to induce IL-1Ra, elevated baseline IL-1Ra levels were associated with better therapeutic outcomes (odds ratio 1.82 [95% confidence interval 1.1-3.29], P = 0.027).


CONCLUSION
The plasma type I IFN activity, the IFNbeta/alpha ratio, and the IL-1Ra level were predictive of the therapeutic response in TNF antagonist-treated RA patients, indicating that these parameters might define clinically meaningful subgroups of RA patients with distinct responses to therapeutic agents.
Factors That Determine a Propensity for Cocaine-Seeking Behavior during Abstinence in Rats

Individual differences in locomotor responses to novelty and psychostimulants, and sensitization following repeated drug exposure, predict increased sensitivity to the reinforcing effects of psychostimulants and are thought to underlie vulnerability to drug addiction. This study tested whether these factors determine another core feature of drug addiction, the propensity for drug-seeking behavior during abstinence in rats with prior cocaine-self-administration experience. Low and high response groups for each of these factors were determined in outbred rats by the median locomotor response to novelty and amphetamine prior to cocaine self-administration (pre-test), and to amphetamine during abstinence (post-test). Cocaine-seeking behavior during abstinence was measured by the level of drug-paired lever responding during extinction, and also during reinstatement induced by cocaine-associated cues, an amphetamine priming injection, and footshock stress. Animals with low and high locomotor responses to novelty and the amphetamine pre-test showed similar levels of cocaine-seeking behavior during extinction and reinstatement testing. Locomotor responses to amphetamine following cocaine self-administration (post-test) also failed to determine amphetamine's ability to reinstate cocaine-seeking behavior. Conversely, high levels of amphetamine-induced reinstatement were associated specifically with escalating cocaine intake during prior self-administration. These animals also developed locomotor sensitization to amphetamine following cocaine self-administration (post-test vs. pre-test), but the capacity to develop locomotor sensitization was not sufficient to determine a propensity for cocaine-seeking behavior. The findings suggest that the relationship between locomotor responses to novelty, amphetamine and behavioral sensitization a,nd the propensity for cocaine-seeking behavior during abstinence is complex, while the level of drug intake during prior self-administration is a primary determinant of this behavior.
Relative bradycardia in hypotensive trauma patients: a reappraisal.

BACKGROUND
The inability to mount tachycardia (T) after trauma-related hypotension is labeled relative bradycardia (RB). The objective of this study was to examine RB incidence and prognosis in a large cohort of patients.


METHODS
The Los Angeles County Trauma System database, consisting of five Level I and eight Level II trauma centers, was queried for all adult (>14 years) hypotensive (systolic blood pressure [SBP] <or=90) trauma patients admitted between 1998 and 2005. RB was defined as SBP <or=90 with heart rate (HR) <or=90, and T was defined as SBP <or=90 with HR >90. Demographics, injury severity, mechanism, and outcomes were compared between the RB and T groups. Multivariate logistic regression was used to determine significant risk factors for mortality.


RESULTS
Of 130,906 adult trauma patients, 7,123 (5.4%) were hypotensive. After excluding patients dead on arrival and those with missing data, 3,727 patients were identified. RB was observed in 1,630 (44%) of patients, whereas T was observed in 2,097 patients (56%). RB patients were older (39.8 +/- 18.6 years vs. 35.3 +/- 17.0 years, p < 0.0001), less severely injured (injury severity score 18.0 +/- 14.2 vs. 20.5 +/- 15.3, p < 0.0001), more hypotensive (SBP 64.7 +/- 31.6 vs. 76.2 +/- 15.1, p < 0.0001), and had less abdominal trauma (abdomen abbreviated injury score 2.9 +/- 1.2 vs. 3.2 +/- 1.1, p < 0.0001) than their tachycardic counterparts. In addition, the mortality was significantly higher in the RB group compared with the T group (30.1% vs. 22.6%, p < 0.0001). Overall, RB had a higher mortality among all subgroups except older patients (age >or=55; 27.7% vs. 35.2%, p = 0.045) and patients with a higher Glasgow coma scale score (>or=12; 5.3% vs. 11.2%, p < 0.0001). Logistic regression identified RB as an independent risk factor for mortality (odds ratio, 1.60; 95% confidence interval, 1.33-1.94; p < 0.0001). When RB was further divided into two groups, observed mortality for HR <60 and HR 60 to 90 was 62.4% and 9.7%, respectively.


CONCLUSIONS
RB was common in hypotensive adult trauma patients; overall, it was associated with increased mortality. Patients older than 55 years and with a higher Glasgow coma scale score demonstrated decreased mortality with RB. When RB was further divided, a HR between 60 and 90 demonstrated a significant lower mortality compared with a HR <60 and to T.
Molecular mechanisms of corticosteroid synergy with thyroid hormone during tadpole metamorphosis.

Corticosteroids (CS) act synergistically with thyroid hormone (TH) to accelerate amphibian metamorphosis. Earlier studies showed that CS increase nuclear 3,5,3'-triiodothyronine (T(3)) binding capacity in tadpole tail, and 5' deiodinase activity in tadpole tissues, increasing the generation of T(3) from thyroxine (T(4)). In the present study we investigated CS synergy with TH by analyzing expression of key genes involved in TH and CS signaling using tadpole tail explant cultures, prometamorphic tadpoles, and frog tissue culture cells (XTC-2 and XLT-15). Treatment of tail explants with T(3) at 100 nM, but not at 10 nM caused tail regression. Corticosterone (CORT) at three doses (100, 500 and 3400 nM) had no effect or increased tail size. T(3) at 10 nM plus CORT caused tails to regress similar to 100 nM T(3). Thyroid hormone receptor beta (TRbeta) mRNA was synergistically upregulated by T(3) plus CORT in tail explants, tail and brain in vivo, and tissue culture cells. The activating 5' deiodinase type 2 (D2) mRNA was induced by T(3) and CORT in tail explants and tail in vivo. Thyroid hormone increased expression of glucocorticoid (GR) and mineralocorticoid receptor (MR) mRNAs. Our findings support that the synergistic actions of TH and CS in metamorphosis occur at the level of expression of genes for TRbeta and D2, enhancing tissue sensitivity to TH. Concurrently, TH enhances tissue sensitivity to CS by upregulating GR and MR. Environmental stressors can modulate the timing of tadpole metamorphosis in part by CS enhancing the response of tadpole tissues to the actions of TH.