223 research outputs found
Intraoperative near-infrared molecular imaging for diagnostic thoracoscopy in difficult clinical scenario
Significance of the Presence of Microscopic Vascular Invasion After Complete Resection of Stage I–II pT1-T2N0 Non-small Cell Lung Cancer and Its Relation with T-Size Categories: Did the 2009 7th Edition of the TNM Staging System Miss Something?
Introduction:The aim of this study was to assess the significance of microscopic vascular invasion (MVI) in a population of resected patients with early-stage non-small cell lung cancer (NSCLC), along with an analysis of the effect of the combination of MVI and tumor size for the T-size categories T1a-T2b according to the 2009 7th edition of the tumor, node, metastasis (TNM) classification.Methods:From January 1993 to August 2008, 746 patients with pT1-T2N0 NSCLC received resection at our institution. MVI was ascertained using histopathological and immunohistochemical techniques.Results:MVI was observed in 257 patients (34%). Prevalence was higher in adenocarcinoma (ADK) than in squamous cell carcinoma (p = 0.002). A significant correlation was found between MVI and ADK (p = 0.03), increased tumor dimension (p = 0.05), and the presence of tumor-infiltrating lymphocytes (p = 0.02). The presence of MVI was associated with a reduced 5-year survival overall (p = 0.003) and in ADK (p = 0.0002). In a multivariate survival analysis, MVI was an indicator of poor survival overall (p = 0.003) and in ADK (p = 0.0005). In each T category (T1a-T2b) of the 2009 TNM staging system, survival of MVI+ patients was significantly lower than the corresponding MVI− patients; T1a and T1b MVI+ patients had a survival similar to MVI− T2 patients.Conclusions:The finding of MVI in pT1-T2N0 NSCLC is frequent. MVI correlates with adenocarcinoma histotype, increased tumor dimensions, and tumor-infiltrating lymphocytes. The presence of MVI is an independent negative prognostic factor. In our experience, MVI was a stronger prognostic indicator than T size in T1a-T2b categories according to the 2009 TNM staging system
Perturbations of slowly rotating black holes: massive vector fields in the Kerr metric
We discuss a general method to study linear perturbations of slowly rotating
black holes which is valid for any perturbation field, and particularly
advantageous when the field equations are not separable. As an illustration of
the method we investigate massive vector (Proca) perturbations in the Kerr
metric, which do not appear to be separable in the standard Teukolsky
formalism. Working in a perturbative scheme, we discuss two important effects
induced by rotation: a Zeeman-like shift of nonaxisymmetric quasinormal modes
and bound states with different azimuthal number m, and the coupling between
axial and polar modes with different multipolar index l. We explicitly compute
the perturbation equations up to second order in rotation, but in principle the
method can be extended to any order. Working at first order in rotation we show
that polar and axial Proca modes can be computed by solving two decoupled sets
of equations, and we derive a single master equation describing axial
perturbations of spin s=0 and s=+-1. By extending the calculation to second
order we can study the superradiant regime of Proca perturbations in a
self-consistent way. For the first time we show that Proca fields around Kerr
black holes exhibit a superradiant instability, which is significantly stronger
than for massive scalar fields. Because of this instability, astrophysical
observations of spinning black holes provide the tightest upper limit on the
mass of the photon: mv<4x10^-20 eV under our most conservative assumptions.
Spin measurements for the largest black holes could reduce this bound to
mv<10^-22 eV or lower.Comment: v1: 29 pages, 9 figures, 3 appendices. v2: References added and
improved discussion. Matches the version to appear in Physical Review D.
Mathematica notebooks available here http://blackholes.ist.utl.pt/?page=Files
and http://www.phy.olemiss.edu/~berti/qnms.htm
Brief practical clinical diagnostic criteria for the neurodegenerative diseases in the elderly
In the literature there is need of clinical and instrumental characterization of all neurodegenerative diseases. Particular attention deserves the timing of the onset of motor or cognitive symptoms, which is extremely useful issue giving the frequent overlapping between neurodegenerative diseases. Aim of this review is to provide a description of typical clinical and imaging features of all neurodegenerative diseases, especially idiopathic Parkinson's disease (PD) and Alzheimer's disease (AD). Particular attention will be devoted to the cluster of symptoms at the moment of the diagnosis. Based on early starting symptoms (cognitive or extrapiramidal) we will introduce criteria to differentiate AD from fronto-Temporal Dementia (FTD), Lewy bodies dementia (DLB) and Vascular dementia (VaD), and between PD, Vascular Parkinsonism (VP) and DLB. All these diseases are characterized by cognitive deficits. PD will be suspected if cognitive impairment occurs at least one year after the onset of the motor symptoms while VP and DLB are more likely if cognitive deficits and motor symptoms appear simultaneously. Finally, we will focus on parkinsonian signs plus other motor symptoms at the time of the diagnosis. The presence of cerebellar or pyramidal signs, with falls and autonomic dysfunction, with or without cognitive deficit should help to consider potential causes of atypical parkinsonism including cortical-basal degeneration (CBD), multiple system atrophy (MSA) and progressive supranuclear palsy (PSP)
Surgery of colorectal cancer lung metastases: analysis of survival, recurrence and re-surgery
BACKGROUND: Surgery is considered an effective therapeutic option for patients with lung metastasis (MTS) of colorectal cancer (CRC). The purpose of the study was to evaluate efficacy and feasibility of lung metastasectomy in CRC patients and to explore factors of prognostic relevance. METHODS: This is a retrospective study of patients operated for lung MTS of CRC from 2004 to 2012 in a single Institution. Overall survival (OS) was the primary endpoint. Secondary endpoints were progression free survival (PFS) in resection status R0 and OS in in patients submitted to re-resections. In order to evaluate prognostic factors, a multivariable Cox proportional hazard model was performed. RESULTS: One-hundred eighty-eight consecutive patients were included in the final analysis. The median follow-up (FU) was 45 months. The 5-year OS and PFS were 53% (95% CI: 44–60%) and 33% (95% CI: 25–42%), respectively. Two- and 5-year survival after re-resection were 79% (95% CI: 63–89%) and 49% (95% CI: 31–65%), respectively. Multivariate adjusted analysis showed that primary CRC pathological TNM stages (P=0.019), number of resected MTS ≥5 (P=0.009) and lymph nodal involvement (P<0.0001) are independent predictors of poor prognosis. CONCLUSIONS: Patients operated and re-operated for lung MTS from CRC cancers showed encouraging survival rates. Our results indicated that primary CRC stage, number of MTS and lymph nodal involvement are strong predictive factors. Prognosis after surgery remained comforting up to four resected MTS. Adjuvant chemotherapy seems to have a benefit on survival in patients affected by multiple metastases. Finally, according to the high rate of unidentified lymph node involvement in pre-operative setting, lymph node sampling should be advisable for a correct staging
Digital versus traditional air leak evaluation after elective pulmonary resection: A prospective and comparative mono-institutional study
BACKGROUND: The increased demand to reduce costs and hospitalization in general pushed several institution worldwide to develop fast-tracking protocols after pulmonary resections. One of the commonest causes of protracted hospital stay remains prolonged air leaks (ALs). We reviewed our clinical practice with the aim to compare traditional vs. digital chest drainages in order to evaluate which is the more effective to correctly manage the chest tube after pulmonary resection. METHODS: All patients submitted to elective pulmonary resection for lung malignancies, between April to December, 2014 in our General Thoracic Surgery Department were included in the study. The primary outcome was the chest tube duration, the secondary the postoperative overall hospitalization. Significant differences between traditional and digital groups were investigated with logistic regression models. Numerical variables between the groups were compared by means of the unpaired Wilcoxon-Mann-Whitney test. RESULTS: Both series of patients were comparable for clinical, surgical and pathological characteristics. Chest tube duration showed to be significantly shorter in the digital group (3 vs. 5 days, P=0.0009), while the hospitalization was longer in traditional one [8 vs. 7 days in digital drainage (DD); P=0.0385]. No chest drainage replacement was required at 30-day, in both groups. CONCLUSIONS: We were able to demonstrate that patients managed with a digital system experienced a shorter chest tube duration as well as a lower overall hospital length of stay, compared to those who received the traditional drainage (TD)
The vacuum revealed: the final state of vacuum instabilities in compact stars
Quantum fields in compact stars can be amplified due to a semiclassical
instability. This generic feature of scalar fields coupled to curvature may
affect the birth and the equilibrium structure of relativistic stars. We point
out that the semiclassical instability has a classical counterpart, which
occurs exactly in the same region of the parameter space. For negative values
of the coupling parameter the instability is equivalent to the well-known
"spontaneous scalarization" effect: the plausible end-state of the instability
is a static, asymptotically flat equilibrium configuration with nonzero
expectation value for the quantum fields, which is compatible with experiments
in the weak-field regime and energetically favored over stellar solutions in
general relativity. For positive values of the coupling parameter the new
configurations are energetically disfavored, and the end-point of the
instability remains an open and interesting issue. The vacuum instability may
provide a natural mechanism to produce spontaneous scalarization, leading to
new experimental opportunities to probe the nature of vacuum energy via
astrophysical observations of compact stars.Comment: 5 pages, 4 figures. v2: one author added; improved discussion of the
results; one figure added. Version accepted in PRD as a Rapid Communicatio
When size matters: changing opinion in the management of pleural space-the rise of small-bore pleural catheters
Tube thoracostomy is usually the first step to treat several thoracic/pleural conditions such as pneumothorax, pleural effusions, haemothorax, haemo-pneumothorax and empyema. Today, a wide range of drains is available, ranging from small to large bore ones. Indications for an appropriate selection remains yet matter of debate, especially regarding the use of small bore catheters. Through this paper, we aimed to retrace the improvements of drains through the years and to review the current clinical indications for chest drain placement in pleural/thoracic diseases, comparing the effectiveness of small-bore drains vs. large-bore ones
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