349 research outputs found
Toward a Systematic Evidence-Base for Science in Out-of-School Time: The Role of Assessment
Analyzes the tools used in assessments of afterschool and summer science programs, explores the need for comprehensive tools for comparisons across programs, and discusses the most effective structure and format for such a tool. Includes recommendations
Teflon Injection into the Trachea Causes Predictable Fibroblastic Response and Collagen Deposition: A Pilot Study.
BackgroundExpiratory central airway collapse is an increasingly recognized abnormality of the central airways and may be present in as many as 22% of patients evaluated for chronic obstructive pulmonary disease and/or asthma. Many current treatment options require invasive procedures that have been shown to cause significant morbidity and mortality. To test the hypothesis that Teflon injection will induce sufficient fibroblast proliferation and collagen deposition, we evaluated the time course on the effect of Teflon injection in the posterior membranous trachea on the histopathology of the tracheobronchial tree.MethodsSix Yucatan Pigs were assigned to undergo general anesthesia and injection of 0.3 to 0.5 mL of sterile Teflon paste in 50% glycerin into the posterior membranous tracheal wall. A control pig received an equivalent volume of glycerin. Animals were euthanized in predefined intervals and tracheas were excised and examined under light microscopy for identifying fibroblast proliferation and collagen deposition.ResultsCompared with the control pig, the Teflon injection site showed tissue reaction of fibrohistiocytic proliferation and subsequent collagen deposition in all animals. Furthermore, the increased fibroblast proliferation and collagen deposition were time dependent (P<0.01).ConclusionThis pilot study demonstrates histopathologic changes in the trachea after Teflon injection, comprised of increased fibroblast activity and collagen deposition that could be of potential use in creating greater airway rigidity in patients with sever diffuse excessive dynamic airway collapse
Expert Opinion International Task Force Criteria for the Clinical Diagnosis of Arrhythmogenic Right Ventricular Cardiomyopathy
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Impact of lung cancer screening results on participant health-related quality of life and state anxiety in the National Lung Screening Trial
BACKGROUND Low-dose computed tomography (LDCT) lung screening has been associated with a 20% reduction in lung cancer mortality. A major barrier to the adoption of lung screening is the potential negative psychological impact of a false-positive (FP) screen, occurring in 20% to 50% of those screened. The objective of this study was to assess the impact of abnormal findings on health-related quality of life (HRQoL) and anxiety in the American College of Radiology (ACRIN)/National Lung Screening Trial (NLST). METHODS The NLST was a randomized screening trial comparing LDCT with chest X-ray screening (CXR). This study was part of the original protocol. A total of 2812 participants at 16 of 23 ACRIN sites who had baseline HRQoL assessments were asked to complete the Short Form-36 and the State Trait Anxiety Inventory (form Y-1) questionnaires to assess short-term (1 month) and long-term (6 months) effects of screening. FP were lung cancer–free at 1 year, and true-positives (TP) were not. RESULTS Of the total participants, 1024 (36.4%) participants were FP, 63 (2.2%) were TP, 344 (12.2%) had significant incidental findings (SIFs), and 1381 (49.1%) had negative screens. Participants had been randomized to LDCT (n = 1947) and CXR (n = 865). Short-term and long-term HRQoL and state anxiety did not differ across participants with FP, SIF, or negative screens. Short-term and long-term HRQoL were lower and anxiety was higher for TP participants compared to participants with FP, SIF, and negative screens. CONCLUSIONS In a large multicenter lung screening trial, participants receiving a false-positive or SIF screen result experienced no significant difference in HRQoL or state anxiety at 1 or at 6 months after screening relative to those receiving a negative result. Cancer 2014;120:3401–3409. © 2014 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. In a large multi-center lung screening trial, participants receiving a false positive or significant incidental finding screen result experienced no significant difference in health related quality of life or state anxiety at 1 or at 6 months after screening relative to those receiving a negative result
Radiation dose management in thoracic CT: an international survey
PURPOSEWe aimed to examine current practice patterns of international thoracic radiologists regarding radiation dose management in adult thoracic computed tomography (CT) examinations. MATERIALS AND METHODSAn electronic questionnaire was sent to 800 members of five thoracic radiology societies in North America, Europe, Asia, and Latin America addressing radiation dose training and education, standard kVp and mAs settings for thoracic CT, dose reduction practices, clinical scenarios, and demographics. RESULTSOf the 800 radiologists, 146 responded to our survey. Nearly half (66/146, 45% [95% confidence interval, 37%–53%]) had no formal training in dose reduction, with “self-study of the literature” being the most common form of training (54/146, 37% [29%–45%]). One hundred and seventeen (80% [74%–87%]) had automatic exposure control, and 76 (65% [56%–74%]) used it in all patients. Notably, most respondents (89% [84%–94%]) used a 120 to 125 kVp standard setting, whereas none used 140 kVp. The most common average dose-length-product (DLP) value was 150 to 249 mGy.cm (75/146, 51% [43%–59%]), and 59% (51%–67%) delivered less than 250 mGy.cm in a 70 kg patient. There was a tendency towards higher DLP values with multidetector-row CT. Age, gender, and pregnancy were associated more with dose reduction than weight and clinical indication. CONCLUSIONEfforts for reducing patient radiation dose are highly prevalent among thoracic radiologists. Areas for improvement include reduction of default tube current settings, reduction of anatomical scan coverage, greater use of automatic exposure control, and eventually, reduction of current reference dose values. Our study emphasizes the need for international guidelines to foster greater conformity in dose reduction by thoracic radiologists
Understanding the total airway response to exercise: current perspectives and future challenges
Exercise places a unique set of physiological demands on the airway tract. Historically, most work in this area has focused on the lower airway response, however it is now becoming increasingly apparent that the structural and functional behaviour of the upper airway and large central airways is equally important. Dysfunction in these sections of the airway tract can act to either hinder or modulate the exercise ventilatory response and as such lead to an increased work of breathing and the development of troublesome respiratory symptoms. This article provides an overview of the way in which the entire airway tract is challenged by the heightened ventilatory state mandated by physical activity, highlighting recent developments in our understanding of the physiology of laryngeal, large central and lower airway function during exercise
Reversed halo sign in pneumocystis pneumonia: a case report
<p>Abstract</p> <p>Background</p> <p>The reversed halo sign may sometimes be seen in patients with cryptogenic organizing pneumonia, but is rarely associated with other diseases.</p> <p>Case presentation</p> <p>We present a case study of a 32-year-old male patient with acquired immunodeficiency syndrome, who had previously been treated with chemotherapy for non-Hodgkin's lymphoma. A chest X-ray showed bilateral patchy infiltrates. High-resolution computed tomography revealed the reversed halo sign in both upper lobes. The patient was diagnosed with pneumocystis pneumonia, which was successfully treated with sulfamethoxazole trimethoprim; the reversed halo sign disappeared, leaving cystic lesions. Cases such as this one are rare, but show that the reversed halo sign may occur in patients who do not have cryptogenic organizing pneumonia.</p> <p>Conclusion</p> <p>Physicians can avoid making an incorrect diagnosis and prescribing the wrong treatment by carefully evaluating all clinical criteria rather than assuming that the reversed halo sign only occurs with cryptogenic organizing pneumonia.</p
Chest radiographs for acute lower respiratory tract infections (Review)
Background: Acute lower respiratory tract infections (LRTIs) (e.g. pneumonia) are a major cause of morbidity and mortality and management focuses on early treatment. Chest radiographs (X-rays) are one of the commonly used strategies. Although radiological facilities are easily accessible in high-income countries, access can be limited in low-income countries. The efficacy of chest radiographs as a tool in the management of acute LRTIs has not been determined. Although chest radiographs are used for both diagnosis and management, our review focuses only on management. Objectives: To assess the effectiveness of chest radiographs in addition to clinical judgement, compared to clinical judgement alone, in the management of acute LRTIs in children and adults. Search methods: We searched CENTRAL 2013, Issue 1; MEDLINE (1948 to January week 4, 2013); EMBASE (1974 to February 2013); CINAHL (1985 to February 2013) and LILACS (1985 to February 2013). We also searched NHS EED, DARE, ClinicalTrials.gov and WHO ICTRP (up to February 2013). Selection criteria: Randomised controlled trials (RCTs) of chest radiographs versus no chest radiographs in acute LRTIs in children and adults. Data collection and analysis: Two review authors independently applied the inclusion criteria, extracted data and assessed risk of bias. A third review author compiled the findings and any discrepancies were discussed among all review authors. We used the standard methodological procedures expected by The Cochrane Collaboration. Main results: Two RCTs involving 2024 patients (1502 adults and 522 children) were included in this review. Both RCTs excluded patients with suspected severe disease. It was not possible to pool the results due to incomplete data. Both included trials concluded that the use of chest radiographs did not result in a better clinical outcome (duration of illness and of symptoms) for patients with acute LRTIs. In the study involving children in South Africa, the median time to recovery was seven days (95% confidence interval (CI) six to eight days (radiograph group) and six to nine days (control group)), P value = 0.50, log-rank test) and the hazard ratio for recovery was 1.08 (95% CI 0.85 to 1.34). In the study with adult participants in the USA, the average duration of illness was 16.9 days versus 17.0 days (P value > 0.05) in the radiograph and no radiograph groups respectively. This result was not statistically significant and there were no significant differences in patient outcomes between the groups with or without chest radiograph. The study in adults also reports that chest radiographs did not affect the frequencies with which clinicians ordered return visits or antibiotics. However, there was a benefit of chest radiographs in a subgroup of the adult participants with an infiltrate on their radiograph, with a reduction in length of illness (16.2 days in the group allocated to chest radiographs and 22.6 in the non-chest radiograph group, P < 0.05), duration of cough (14.2 versus 21.3 days, P < 0.05) and duration of sputum production (8.5 versus 17.8 days, P < 0.05). The authors mention that this difference in outcome between the intervention and control group in this particular subgroup only was probably a result of "the higher proportion of patients treated with antibiotics when the radiograph was used in patient care". Hospitalisation rates were only reported in the study involving children and it was found that a higher proportion of patients in the radiograph group (4.7%) required hospitalisation compared to the control group (2.3%) with the result not being statistically significant (P = 0.14). None of the trials report the effect on mortality, complications of infection or adverse events from chest radiographs. Overall, the included studies had a low or unclear risk for blinding, attrition bias and reporting bias, but a high risk of selection bias. Both trials had strict exclusion criteria which is important but may limit the clinical practicability of the results as participants may not reflect those presenting in clinical practice. Authors' conclusions: Data from two trials suggest that routine chest radiography does not affect the clinical outcomes in adults and children presenting to a hospital with signs and symptoms suggestive of a LRTI. This conclusion may be weakened by the risk of bias of the studies and the lack of complete data available
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