256 research outputs found
Mid-IR Enhanced Galaxies in the Coma & Virgo Cluster: lenticulars with a high star formation rate
We explore the properties of early-type galaxies (ETGs), including
ellipticals (E) and lenticulars (S0), in rich environments such as clusters of
galaxies (Virgo and Coma). The L_24/L_K distribution of ETGs in both Virgo and
Coma clusters shows that some S0s have a much larger L_24/L_K ratio (0.5 to ~2
dex) than the bulk of the ETG population. This could be interpreted as an
enhanced star formation rate in these lenticulars. We compare the optical
colors of galaxies in these two clusters and investigate the nature of these
sources with a large L24/L_K ratio by looking at their spatial distribution
within the cluster, by analyzing their optical spectra and by looking at their
optical colors compared to late-types. We obtain 10 Coma and 3 Virgo early-type
sources with larger L24/L_K ratios than the bulk of their population. We call
these sources Mid-Infrared Enhanced Galaxies (MIEGs). In Coma, they are mostly
located in the South-West part of the cluster where a substructure is falling
onto the main cluster. MIEGs present lower g-r color than the rest of the ETG
sample, because of a blue continuum. We interpret the excess L24/L_K ratio as
evidence for an enhanced star-formation induced as a consequence of their
infall into the main cluster.Comment: Accepted for publication in Ap
Updated management of malignant biliary tract tumors: an illustrative review
The management of malignant biliary tumors (MBTs) is complex and requires a multidisciplinary approach. Guidelines and methods of staging for biliary tumors have recently been released by main international societies, altering the clinical and radiologic approach to this pathologic condition. The aim of the present review is to detail the updated role of imaging in preoperative staging and follow-up and to illustrate clinical/therapeutic pathways. In addition, future perspectives on imaging and targeted/embolization therapies are outlined
Percutaneous Treatment of Malignant Jaundice Due to Extrahepatic Cholangiocarcinoma: Covered Viabil Stent Versus Uncovered Wallstents
To compare clinical effectiveness of Viabil-covered stents versus uncovered metallic Wallstents, for palliation of malignant jaundice due to extrahepatic cholangiocarcinoma, 60 patients were enrolled in a prospective and randomized study. In half of the patients a bare Wallstent was used, and in the other half a Viabil biliary stent. Patients were followed up until death. Primary patency, survival, complication rates, and mean cost were calculated in both groups. Stent dysfunction occurred in 9 (30%) patients in the bare stent group after a mean period of 133.1 days and in 4 (13.3%) patients in the covered stent group after a mean of 179.5 days. The incidence of stent dysfunction was significantly lower in the covered stent group (P = 0.046). Tumor ingrowth occurred exclusively in the bare stent group (P = 0.007). Median survival was 180.5 days for the Wallstent and 243.5 days for the Viabil group (P = 0.039). Complications and mean cost were similar in the two groups. Viabil stent-grafts proved to be significantly superior to Wallstents for the palliation of malignant jaundice due to extrahepatic cholangiocarcinoma, with comparable cost and complication rates. Appropriate patient selection should be performed prior to stent placement
Management of malignant biliary obstruction: Technical and clinical results using an expanded polytetrafluoroethylene fluorinated ethylene propylene (ePTFE/FEP)-covered metallic stent after 6-year experience
To evaluate the efficacy and safety of an expanded polytetrafluoroethylene- fluorinated ethylene-propylene (ePTFE/FEP)-covered metallic stent in the management of malignant biliary obstruction. Eighty consecutive patients with malignant common bile duct strictures were treated by placement of 83 covered metallic stents. The stent-graft consists of an inner ePTFE/FEP lining and an outer supporting structure of nitinol wire. Clinical evaluation, assessment of serum bilirubin and liver enzyme levels were analyzed before biliary drainage, before stent-graft placement and during the follow-up period at 1, 3, 6, 9 and 12 months. Technical success was obtained in all cases. After a mean follow-up of 6.9±4.63 months, the 30-day mortality rate was 14.2%. Survival rates were 40% and 20.2% at 6 and 12 months, respectively. Stent-graft patency rates were 95.5%, 92.6% and 85.7% at 3, 6 and 12 months, respectively. Complications occurred in five patients (6.4%); among these, acute cholecystitis was observed in three patients (3.8%). A stent-graft occlusion rate of 9% was observed. The percentage of patients undergoing lifetime palliation (91%) and the midterm patency rate suggest that placement of this ePTFE/FEP-covered stent-graft is safe and highly effective in achieving biliary drainage in patients with malignant strictures of the common bile duct. © 2008 European Society of Radiology
Risk Factors for Immediate and Delayed-Onset Fever After Percutaneous Transhepatic Biliary Drainage
Objectives To prospectively investigate the pre and intraprocedural risk factors for immediate (IF) and delayedonset (DOF) fever development after percutaneous transhepatic biliary drainage (PTBD).
Methods Institutional review board approval and
informed patient consent were obtained. Between February
2013 and February 2014, 97 afebrile patients (77 at the
Sapienza University of Rome, Italy and 20 at the Sun Yatsen University of Guangzhou, China) with benign (n = 31)
and malignant (n = 66) indications for a first PTBD were
prospectively enrolled. Thirty pre- and intra-procedural
clinical/radiological characteristics, including the amount
of contrast media injected prior to PTBD placement, were
collected in relation to the development of IF (within 24 h)
or DOF (after 24 h). Fever was defined as C37.5 C.
Binary logistic regression analysis was used to assess
independent associations with IF and DOF.
Results Fourteen (14.4 %) patients developed IF and 17
(17.5 %) developed DOF. At multivariable analysis, IF
was associated with pre-procedural absence of intrahepatic
bile duct dilatation (OR 63.359; 95 % CI 2.658–1510.055;
P = 0.010) and low INR (OR 4.7 9 10-4
; 95 % CI
0.000–0.376; P = 0.025), while DOF was associated with
unsatisfactory biliary drainage at the end of PTBD (OR
4.571; 95 % CI 1.161–17.992; P = 0.030)
Anticoagulation in Peripheral Artery Disease: Are We There Yet?
Thromboembolism in patients with peripheral artery disease (PAD) represents a common cause of morbidity and mortality. In this article, the authors analyse the use of anticoagulants for patients with PAD. Anticoagulants have been used to reduce the risk of venous thromboembolism, but have recently been applied to the arterial circulation. Heparins were introduced to reduce short-term major adverse limb events in patients undergoing arterial revascularisation. Low molecular weight heparins have allowed easier management and carry a lower risk of bleeding than unfractioned heparin. Vitamin K anticoagulants have been tested in trials that included patients with PAD, showing an increased risk of bleeding when compared with aspirin alone, but longer patency rates for venous surgical bypass, although the evidence remains weak. Those anticoagulants are currently recommended only in patients with PAD who need anticoagulation for other diseases. Direct oral anticoagulants have only recently been investigated for use in patients with PAD. Promising results from low dose rivaroxaban plus aspirin have been recently outlined by a randomised controlled trial and supported by international guidelines
Femoral artery ultrasound examination: a new role in predicting cardiovascular risk
We compared intima-media thickness (IMT) and the prevalence of plaques in the common carotid artery (CCA) and common femoral artery (CFA) in apparently healthy participants. This multicenter study included 322 participants (59.9% female; age 20-78 years, mean 52.1 ± 15.3 years) who underwent Echo-color Doppler examination of the CCA and CFA bilaterally. Prevalence and composition of plaque were recorded. A significant ( P < .01) difference between mean CCA-IMT and mean CFA-IMT was detected (0.70 vs 0.73 mm). Plaque prevalence was significantly higher in the CFA compared to the CCA (40.7% vs 30.4%). Atherosclerotic plaques were found in both CFA and CCA in 46% of the cases, solely in CFA in 38%, and in CCA alone in 17%. The observed difference in plaque prevalence was even greater when only fibrolipid isolated plaques were considered (CFA 39.4% vs CCA 22.1%). In a healthy general population, atherosclerotic plaques were present in the CFA but not in the CCA in over one-third of the cases. Further studies must confirm whether ultrasonography of the CFA might be introduced in the screening protocols for cardiovascular risk assessment
Chlamydophila pneumoniae infection in patients undergoing carotid artery stent.
Although several reports have correlated Chlamydophila pneumoniae (CP) infection with carotid endarterectomy and coronary stent, no data have been reported on the potential relationship between this pathogen and carotid artery stenting (CAS). Hence, we evaluated 47 subjects, 27 symptomatic and 20 asymptomatic, before CAS intervention and during the follow up, for the presence of CP DNA and anti-CP antibodies, including chlamydial HSP60 (Cp-HSP60). Before stent placement, CP DNA was detected exclusively in symptomatic patients, all of whom were also positive for CP IgG and IgA and 85.7% of them also had CP-HSP60 antibodies. At the follow-up, all CP DNA positive and 11 out of the 13 symptomatic patients with Cp-HSP60 antibodies became negatives. In contrast, no change was observed for CP- IgA antibodies. Despite the small number of patients, the present study advocates an important role of CP infection in symptomatic patients with carotid artery disease. Our findings also suggest that stent placement and/or therapy might have a role in favouring resolution of inflammation, though not affecting persistence of CP infection
First Phase Space Portrait of a Hierarchical Stellar Structure in the Milky Way
We present the first detailed observational picture of a possible ongoing
massive cluster hierarchical assembly in the Galactic disk as revealed by the
analysis of the stellar full phase-space (3D positions and kinematics and
spectro-photometric properties) of an extended area ( diameter)
surrounding the well-known and Persei double stellar cluster in
the Perseus Arm. Gaia-EDR3 shows that the area is populated by seven co-moving
clusters, three of which were previously unknown, and by an extended and quite
massive () halo. All stars and clusters define a complex
structure with evidence of possible mutual interactions in the form of
intra-cluster over-densities and/or bridges. They share the same chemical
abundances (half-solar metallicity) and age ( Myr) within a small
confidence interval and the stellar density distribution of the surrounding
diffuse stellar halo resembles that of a cluster-like stellar system. The
combination of these evidences suggests that stars distributed within a few
degrees from and Persei are part of a common, sub-structured
stellar complex that we named LISCA I. Comparison with results obtained through
direct -body simulations suggest that LISCA I may be at an intermediate
stage of an ongoing cluster assembly that can eventually evolve in a relatively
massive (a few ) stellar system. We argue that such cluster
formation mechanism may be quite efficient in the Milky Way and disk-like
galaxies and, as a consequence, it has a relevant impact on our understanding
of cluster formation efficiency as a function of the environment and redshift.Comment: 19 pages, 8 figures, 1 table; accepted for publication in Ap
Management of Acute Kidney Injury and Extracorporeal Blood Purification Therapies During the COVID-19 Pandemic: The Italian SIN-SIAARTI Joint Survey (and Recommendations for Clinical Practice)
Background and aim: The novel coronavirus disease 2019 remains challenging. A large number of hospitalized patients are at a high risk of developing AKI. For this reason, we conducted a nationwide survey to assess the incidence and management of AKI in critically ill patients affected by the SARS-CoV-2 infection. Methods: This is a multicenter, observational, nationwide online survey, involving the Italian Society of Nephrology and the critical care units in Italy, developed in partnership between the scientific societies such as SIN and SIAARTI. Invitations to participate were distributed through emails and social networks. Data were collected for a period of 1 week during the COVID-19 pandemic. Results: A total of 141 responses were collected in the SIN-SIAARTI survey: 54.6% from intensivists and 44.6% from nephrologists. About 19,000 cases of COVID-19 infection have been recorded in hospitalized patients; among these cases, 7.3% had a confirmed acute kidney injury (AKI), of which 82.2% were managed in ICUs. Only 43% of clinicians routinely used the international KDIGO criteria. Renal replacement therapy (RRT) was performed in 628 patients with continuous techniques used most frequently, and oliguria was the most common indication (74.05%). Early initiation was preferred, and RRT was contraindicated in the case of therapeutic withdrawal or in the presence of severe comorbidities or hemodynamic instability. Regional anticoagulation with citrate was the most common choice. About 41.04% of the interviewed physicians never used extracorporeal blood purification therapies (EBPTs) for inflammatory cytokine or endotoxin removal. Moreover, 4.33% of interviewed clinicians used these techniques only in the presence of AKI, whereas 24.63% adopted them even in the absence of AKI. Nephrologists made more use of EBPT, especially in the presence of AKI. HVHF was never used in 58.54% of respondents, but HCO membranes and adsorbents were used in more than 50% of cases. Conclusion: This joint SIN-SIAARTI survey at the Italian Society of Nephrology and the critical care units in Italy showed that, during the COVID-19 pandemic, there was an underestimation of AKI based on the "non-use" of common diagnostic criteria, especially by intensivists. Similarly, the use of specific types of RRT and, in particular, blood purification therapies for immune modulation and organ support strongly differed between centers, suggesting the need for the development of standardized clinical guidelines
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