955 resultados para Small mammals
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Despite decades of research, therapeutic advances in non-small cell lung cancer (NSCLC) have progressed at a painstaking slow rate with few improvements in standard surgical resection for early stage disease and chemotherapy or radiotherapy for patients with advanced disease. In the past 18 months, however, we seemed to have reached an inflexion point: therapeutic advances that are centred on improvements in the understanding of patient selection, surgery that is undertaken through smaller incisions, identification of candidate mutations accompanied by the development of targeted anticancer treatments with a focus on personalised medicine, improvements to radiotherapy technology, emergence of radiofrequency ablation (RFA), and last but by no means least, the recognition of palliative care as a therapeutic modality in its own right. The contributors to this review are a distinguished international panel of experts who highlight recent advances in each of the major disciplines.
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OBJECTIVES: Studies of small area variations of health care utilization are more and more frequent. Such variations are often considered to be an indication of variations in the quality of medical care. The variations in the rate of operations for hip fractures are among the lowest studied to date, due to the fact that a consensus exists concerning this surgery. Our objective is to examine these variations within the context of relatively small and heterogeneous districts. METHOD: Based on anonymous computerized data on public hospital stays, this study describes the variations in population rates (crude and standardized) of operations for hip fracture among the health districts of the Canton of Vaud for the period from 1986 to 1991. District populations vary from 22,000 to 164,000. Using the extremal quotient (EQ), the importance of these variations was determined. RESULTS: The study population consists of 2363 cases, of which 78% are women. Mean age is 80.4 for women and 70.6 for men. Standardized rates of operation for hip fracture per 100,000 in the Canton Vaud for the years 1986 to 1991 are, respectively: 56; 67; 86; 91; 89 and 94. The EQ for the years 1986 to 1991 are respectively: 8.2; 4.0; 3.5; 2.7; 1.9 and 1.9. The high EQ, especially for the earlier years, are contrary to the initial premise of absence of variation. The progressive implementation in the Canton Vaud of VESKA medical statistics could play a role, as could the small size of many of the districts, with resultant instability of rates. CONCLUSIONS: Considering the wide variations shown here for an operation hardly regarded as subject to variations, it is important to exercise caution in interpreting published data of small area variations.
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BACKGROUND: Induction radiochemotherapy, followed by resection, for T4 non-small cell lung cancer, has shown promising long-term survival but may be associated with increased postoperative morbidity and death, depending on patient selection. Here, we determined the effect of induction radiochemotherapy on pulmonary function and whether postinduction pulmonary function changes predict hospital morbidity and death and long-term survival. METHODS: A consecutive prospective cohort of 72 patients with T4 N0-2 M0 non-small cell lung cancer managed by radiochemotherapy, followed by resection, is reported. All patients underwent thoracoabdominal computed tomography or fusion positron emission tomography-computed tomography, brain imaging, mediastinoscopy, echocardiography, ventilation-perfusion scintigraphy, and pulmonary function testing before and after induction therapy. Resection was performed if the postoperative forced expiratory volume in 1 second and diffusion capacity of the lung for carbon monoxide exceeded 30% predicted and if the postoperative maximum oxygen consumption exceeded 10 mL/kg/min. RESULTS: The postoperative 90-day mortality rate was 8% (lobectomy, 2%; pneumonectomy, 21%; p=0.01). All deaths after pneumonectomy occurred after right-sided procedures. The 3-year and 5-year survival was 50% (95% confidence interval, 36% to 62%) and 45% (95% confidence interval, 31% to 57%) and was significantly associated with completeness of resection (p=0.004) and resection type (pneumonectomy vs lobectomy, p=0.01). There was no correlation between postinduction pulmonary function changes and postoperative morbidity or death or long-term survival in patients managed by lobectomy or pneumonectomy. CONCLUSIONS: In properly selected patients with T4 N0-2 M0 non-small cell lung cancer, resection after induction radiochemotherapy can be performed with a reasonable postoperative mortality rate and long-term survival, provided the resection is complete and a right-sided pneumonectomy is avoided. Postinduction pulmonary function changes did not correlate with postoperative morbidity or death or with long-term outcome.
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Abstract
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OBJECTIVES: To assess the performance of 45F vs. 36F smartcanula in CPB with gravity drainage alone. METHODS: Twenty patients were randomly assigned to two groups receiving for venous drainage a smartcanula which is collapsed over a mandrel for trans-atrial insertion into the inferior vena cava and expanded in situ to either 45F or 36F. RESULTS: Valve replacement/repair was realized in 7/10 and/or CABG in 6/10 for 36F (69+/-13 years) vs. 5/10 and 5/10, respectively, for 45F (63+/-11 years: NS). Body weight and surface area (BSA) were 83+/-9 kg (1.9+/-0.2 m2, max 2.2 m2) for 36F vs. 79+/-6 kg: NS (1.9+/-0.1 m2 (NS), max 2.1 m2) for 45F. Insertion and access orifice diameter (area) was 6 mm and 10 mm (78.5 mm2) for the 36F vs. 6 mm and 13 mm (132 mm2) for the 45F (+69%). Calculated target pump flow (2.4 l/min/m2) was 4.7+/-0.4 l/min for 36F vs. 4.5+/-0.3 l/min for 45F. Achieved pump flow accounted for 5.0+/-0.3 l/min for 36F (8% above target) vs. 4.8+/-0.3 l/min for 45F (8% above target): NS. The water balance during the pump run (clear volume added minus hemofilter and urine output) was 2.2+/-0.3 l for 36F vs. 2.0 l for 45F: NS. CONCLUSION: Due to its 'open' wall (the vena cava provides the seal), its reduced wall thickness (range: 0.0-0.4 mm), and its self-expanding design, the 36F smartcanula requiring a 30F access orifice has sufficient drainage capacity by gravity alone for full CPB in adults with a BSA up to 2.2 mm2.
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BACKGROUND: Platinum-based doublet chemotherapy is recommended to treat advanced non-small-cell lung cancer (NSCLC) in fit, non-elderly adults, but monotherapy is recommended for patients older than 70 years. We compared a carboplatin and paclitaxel doublet chemotherapy regimen with monotherapy in elderly patients with advanced NSCLC. METHODS: In this multicentre, open-label, phase 3, randomised trial we recruited patients aged 70-89 years with locally advanced or metastatic NSCLC and WHO performance status scores of 0-2. Patients received either four cycles (3 weeks on treatment, 1 week off treatment) of carboplatin (on day 1) plus paclitaxel (on days 1, 8, and 15) or five cycles (2 weeks on treatment, 1 week off treatment) of vinorelbine or gemcitabine monotherapy. Randomisation was done centrally with the minimisation method. The primary endpoint was overall survival, and analysis was done by intention to treat. This trial is registered, number NCT00298415. FINDINGS: 451 patients were enrolled. 226 were randomly assigned monotherapy and 225 doublet chemotherapy. Median age was 77 years and median follow-up was 30.3 months (range 8.6-45.2). Median overall survival was 10.3 months for doublet chemotherapy and 6.2 months for monotherapy (hazard ratio 0.64, 95% CI 0.52-0.78; p<0.0001); 1-year survival was 44.5% (95% CI 37.9-50.9) and 25.4% (19.9-31.3), respectively. Toxic effects were more frequent in the doublet chemotherapy group than in the monotherapy group (most frequent, decreased neutrophil count (108 [48.4%] vs 28 [12.4%]; asthenia 23 [10.3%] vs 13 [5.8%]). INTERPRETATION: Despite increased toxic effects, platinum-based doublet chemotherapy was associated with survival benefits compared with vinorelbine or gemcitabine monotherapy in elderly patients with NSCLC. We feel that the current treatment paradigm for these patients should be reconsidered. FUNDING: Intergroupe Francophone de Cancérologie Thoracique, Institut National du Cancer.
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Traditionally, the Iowa Department of Transportation has used the Iowa Runoff Chart and single-variable regional-regression equations (RREs) from a U.S. Geological Survey report (published in 1987) as the primary methods to estimate annual exceedance-probability discharge (AEPD) for small (20 square miles or less) drainage basins in Iowa. With the publication of new multi- and single-variable RREs by the U.S. Geological Survey (published in 2013), the Iowa Department of Transportation needs to determine which methods of AEPD estimation provide the best accuracy and the least bias for small drainage basins in Iowa. Twenty five streamgages with drainage areas less than 2 square miles (mi2) and 55 streamgages with drainage areas between 2 and 20 mi2 were selected for the comparisons that used two evaluation metrics. Estimates of AEPDs calculated for the streamgages using the expected moments algorithm/multiple Grubbs-Beck test analysis method were compared to estimates of AEPDs calculated from the 2013 multivariable RREs; the 2013 single-variable RREs; the 1987 single-variable RREs; the TR-55 rainfall-runoff model; and the Iowa Runoff Chart. For the 25 streamgages with drainage areas less than 2 mi2, results of the comparisons seem to indicate the best overall accuracy and the least bias may be achieved by using the TR-55 method for flood regions 1 and 3 (published in 2013) and by using the 1987 single-variable RREs for flood region 2 (published in 2013). For drainage basins with areas between 2 and 20 mi2, results of the comparisons seem to indicate the best overall accuracy and the least bias may be achieved by using the 1987 single-variable RREs for the Southern Iowa Drift Plain landform region and for flood region 3 (published in 2013), by using the 2013 multivariable RREs for the Iowan Surface landform region, and by using the 2013 or 1987 single-variable RREs for flood region 2 (published in 2013). For all other landform or flood regions in Iowa, use of the 2013 single-variable RREs may provide the best overall accuracy and the least bias. An examination was conducted to understand why the 1987 single-variable RREs seem to provide better accuracy and less bias than either of the 2013 multi- or single-variable RREs. A comparison of 1-percent annual exceedance-probability regression lines for hydrologic regions 1–4 from the 1987 single-variable RREs and for flood regions 1–3 from the 2013 single-variable RREs indicates that the 1987 single-variable regional-regression lines generally have steeper slopes and lower discharges when compared to 2013 single-variable regional-regression lines for corresponding areas of Iowa. The combination of the definition of hydrologic regions, the lower discharges, and the steeper slopes of regression lines associated with the 1987 single-variable RREs seem to provide better accuracy and less bias when compared to the 2013 multi- or single-variable RREs; better accuracy and less bias was determined particularly for drainage areas less than 2 mi2, and also for some drainage areas between 2 and 20 mi2. The 2013 multi- and single-variable RREs are considered to provide better accuracy and less bias for larger drainage areas. Results of this study indicate that additional research is needed to address the curvilinear relation between drainage area and AEPDs for areas of Iowa.
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Hysteresis cycles are very important features of energy conversion and harvesting devices, such as batteries. The efficiency of these may be strongly affected by the physical size of the system. Here, we show that in systems which are small enough, the existence of physical boundaries which produce nonhomogeneities of the interaction potential gives rise to inflections and barriers in the associated free energy. This in turn brings on irreversible processes which can be triggered under suitable external conditions imposed by a heat bath. As an example, by controlling the temperature, the state of a small system may be impelled to oscillate between two different structural configurations or aggregation states avoiding equilibrium coexistence and therefore dissipating energy. This cyclical behavior associated with a hysteresis cycle may be prototypical of energy conversion, storage, or generating nanodevices, as exemplified by Li-ion insertion batteries.
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Various pulmonary artery preparations in vitro demonstrate sustained endothelium-dependent contractions upon hypoxia. To determine whether endothelin-1 could mediate this phenomenon, we examined the effect of bosentan, a new antagonist of both the ETA and ETB subtypes of the endothelin receptor. Small (300 pm) pulmonary arteries from rats were mounted on a myograph, precontracted with prostaglandin F2 alpha and exposed to hypoxia (PO2, 10 to 15 mm Hg, measured on-line) for 45 min. Endothelium-intact control rings exhibited a biphasic response, with a transient initial vasoconstriction (phase 1) followed by a second slowly developing sustained contraction (phase 2). Expressed in percent of the maximal response to 80 mmol/L KCl, the amplitudes of phase 1 (peak tension) and 2 (tension after 45 min of hypoxia) averaged 37 +/- 12% and 17 +/- 14%, respectively (n = 11). In endothelium-denuded rings, phase 1 persisted while the amplitude of phase 2 was reduced to 2 +/- 12% (p < 0.05, n = 8), showing the endothelium dependence of this contraction. Neither phase was significantly decreased in rings treated with 10(-5) mmol/L bosentan (38 +/- 15% and 17 +/- 12%, respectively, n = 6). The PO2 threshold for onset of hypoxic contraction was not significantly different among these three groups and averaged 32 +/- 24 mm Hg. In a separate experiment, we assessed the inhibitory effect of 10(-5) mol/L bosentan on the response to 10(-8) mol/L endothelin-I. Rings treated for 45 min with 10(-8) mol/L endothelin-1 alone exhibited a maximal contraction of 75 +/- 27% (n = 6). This was reduced to 4 +/- 17% (p < 0.01, n = 6) in rings treated with both 10(-8) mol/L endothelin-1 and 10(-5) mol/L bosentan. We conclude that complete blockade of all endothelin receptor subtypes has no effect on either endothelium-dependent or -independent hypoxic contractions in this preparation. This suggests that endothelial factors other than endothelin-I mediate the acute hypoxic contractions of small pulmonary arteries in the rat.
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The aim was to investigate the efficacy of neoadjuvant docetaxel-cisplatin and identify prognostic factors for outcome in locally advanced stage IIIA (pN2 by mediastinoscopy) non-small-cell lung cancer (NSCLC) patients. In all, 75 patients (from 90 enrolled) underwent tumour resection after three 3-week cycles of docetaxel 85 mg m-2 (day 1) plus cisplatin 40 or 50 mg m-2 (days 1 and 2). Therapy was well tolerated (overall grade 3 toxicity occurred in 48% patients; no grade 4 nonhaematological toxicity was reported), with no observed late toxicities. Median overall survival (OS) and event-free survival (EFS) times were 35 and 15 months, respectively, in the 75 patients who underwent surgery; corresponding figures for all 90 patients enrolled were 28 and 12 months. At 3 years after initiating trial therapy, 27 out of 75 patients (36%) were alive and tumour free. At 5-year follow-up, 60 and 65% of patients had local relapse and distant metastases, respectively. The most common sites of distant metastases were the lung (24%) and brain (17%). Factors associated with OS, EFS and risk of local relapse and distant metastases were complete tumour resection and chemotherapy activity (clinical response, pathologic response, mediastinal downstaging). Neoadjuvant docetaxel-cisplatin was effective and tolerable in stage IIIA pN2 NSCLC, with chemotherapy contributing significantly to outcomes.
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Abstract
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Topological order has proven a useful concept to describe quantum phase transitions which are not captured by the Ginzburg-Landau type of symmetry-breaking order. However, lacking a local order parameter, topological order is hard to detect. One way to detect it is via direct observation of anyonic properties of excitations which are usually discussed in the thermodynamic limit, but so far has not been realized in macroscopic quantum Hall samples. Here we consider a system of few interacting bosons subjected to the lowest Landau level by a gauge potential, and theoretically investigate vortex excitations in order to identify topological properties of different ground states. Our investigation demonstrates that even in surprisingly small systems anyonic properties are able to characterize the topological order. In addition, focusing on a system in the Laughlin state, we study the robustness of its anyonic behavior in the presence of tunable finite-range interactions acting as a perturbation. A clear signal of a transition to a different state is reflected by the system's anyonic properties.