806 research outputs found
A successful experimental model for intimal hyperplasia prevention using a resveratrol eluting balloon
Objective: Restenosis due to intimal hyperplasia is a major clinical problem that compromises the success of angioplasty
and endovascular surgery. Resveratrol (RSV) has demonstrated a beneficial effect on restenosis from angioplasty. Unfortunately,
the physicochemical characteristics of RSV reduce the practicality of its immediate clinical application. This
work proposes an experimental model aiming to setup an intravessel, elutable, RSV-containing compound.
Methods: A 140 mg/mL RSV sterile injectable solution with a suitable viscosity for intravascular administration by drugdelivery
catheter (RSV-c) was prepared. This solution was locally administered in the common iliac artery of adult male
New Zealand White rabbits using a dedicated device (Genie; Acrostak, Geneva, Switzerland) after the induction of intimal
hyperplasia by traumatic angioplasty. The RSV concentrations in the wall artery were determined, and the thickness of the
harvested iliac arteries was measured over a 1-month period.
Results: The Genie catheter was applied in rabbit vessels, and the local delivery resulted in an effective reduction in restenosis
after plain angioplasty. Notably, RSV-c forced into the artery wall by balloon expansion might accumulate in the interstitial
areas or within cells, avoiding the washout of solutions. Magnification micrographs showed intimal proliferation was
significantly inhibited when RSV-c was applied. Moreover, no adverse events were documented in in vitro or in vivo studies.
Conclusions: RSV can be advantageously administered in the arterial walls by a drug-delivery catheter to reduce the risk of
restenosis
Diagnosis and treatment of acute pancreatitis: The position statement of the Italian Association for the study of the pancreas
BACKGROUND AND AIM:
Till now, no Italian studies providing information on acute pancreatitis have been published. The aim of this study was to evaluate the epidemiological and clinical characteristics of acute pancreatitis in Italy.
MATERIALS AND METHODS:
The study involved 37 Italian centres distributed homogeneously throughout the entire national territory and prospectively collected epidemiological, anamnestic, laboratory, radiological, therapeutic (pharmacological, endoscopic and surgical) data, relevant to each individual case of acute pancreatitis consecutively observed during the period from September 1996 to June 2000.
RESULTS:
One thousand two hundred and six case report forms were collected, but 201 patients (16.6%) were subsequently eliminated from the final analysis. We therefore studied 1005 patients, 533 (53%) males and 472 (47%) females, mean age 59.6 +/- 20 years. On the basis of the Atlanta classification of acute pancreatitis, 753 patients of the 1005 cases analysed (75%) were mild and 252 patients (25%) severe. The aetiology was biliary in 60% of the patients, related to alcohol abuse in 8.5%, while in 21% of the cases it could not be identified. Over 80% of the patients (83%) were admitted to hospital within 24 h from the onset of clinical symptoms, while only 6% were admitted after 48 h. In particular, 65% of the patients were admitted to hospital within the first 12 h. Antibiotics were used in 85% of the severe and 75% of mild forms. Endoscopic therapy was carried out in 65% of the severe cases, but only in 40% it was carried out prior to 72 h. Eighty-five patients (8.5% of the total, 34% of the severe forms) underwent surgical intervention: 20% on the first day, 38.5% within the fourth day, and the remaining (41.5% of the cases) later on for infected necrosis. The mean duration of hospitalisation for patients with mild pancreatitis was 13 +/- 8 days, while for the severe disease it was of 30 +/- 14 days. The overall mortality rate was 5%, 17% in severe and 1.5% in mild pancreatitis.
CONCLUSIONS:
Acute pancreatitis in Italy is more commonly a mild disease with a biliary aetiology. The treatment of the disease is not optimal and, on the basis of these data, needs to be standardised. Despite this, the overall mortality rate is low (5%BACKGROUND AND AIM:
Till now, no Italian studies providing information on acute pancreatitis have been published. The aim of this study was to evaluate the epidemiological and clinical characteristics of acute pancreatitis in Italy.
MATERIALS AND METHODS:
The study involved 37 Italian centres distributed homogeneously throughout the entire national territory and prospectively collected epidemiological, anamnestic, laboratory, radiological, therapeutic (pharmacological, endoscopic and surgical) data, relevant to each individual case of acute pancreatitis consecutively observed during the period from September 1996 to June 2000.
RESULTS:
One thousand two hundred and six case report forms were collected, but 201 patients (16.6%) were subsequently eliminated from the final analysis. We therefore studied 1005 patients, 533 (53%) males and 472 (47%) females, mean age 59.6 +/- 20 years. On the basis of the Atlanta classification of acute pancreatitis, 753 patients of the 10
Ab initio dynamics study of poly-para-phenylene vinylene
We present an ab initio dynamics investigation within a density-functional perturbation theory framework of the properties of the conjugated polymer poly-para-phenylene vinylene (PPV) in both the isolated chain and crystalline states. The calculated results show that for an isolated chain, most of the vibrational modes correspond to experimentally observed modes in crystalline PPV. However, additional hitherto unidentified modes have been observed in experiment and our calculations on crystalline material have allowed us to assign these. We also present the results of calculations of the polarizability and permittivity tensors of the material, which are in reasonable agreement with the typical values for conjugated polymers. Dynamical Born effective charges [ S. Baroni, S. de Gironcoli, A. Dal Corso, and P. Giannozzi, Rev. Mod. Phys. 73, 515 (2001) ] are calculated and compared with atomic charges obtained from Mulliken population analysis [ M. D. Segall, C. J. Pickard, R. Shah, and M. C. Payne, Mol. Phys. 89, 571 (1996) ] and we conclude that effective charges are more appropriate for use in the study of the dynamics of the system. Notable differences are found in the infrared-absorption spectra obtained for the isolated chain and crystalline states, which can be attributed to the differences in the crystalline packing effects, which clearly play a key role in influencing the lattice dynamics of PPV
A flash in the dark: UVES/VLT high resolution spectroscopy of GRB afterglows
We present the first high resolution (R=20000--45000, corresponding to 14
km/s at 4200A to 6.6 km/s at 9000A) observations of the optical afterglow of
Gamma Ray Bursts. GRB020813 and GRB021004 were observed by UVES@VLT 22.19 hours
and 13.52 hours after the trigger, respectively. These spectra show that the
inter--stellar matter of the GRB host galaxies is complex, with many components
contributing to each main absorption system, and spanning a total velocity
range of up to about 3000 km/s. Several narrow components are resolved down to
a width of a few tens of km/s. In the case of GRB021004 we detected both low
and high ionization lines. Combined with photoionization results obtained with
CLOUDY, the ionization parameters of the various systems are consistent with a
remarkably narrow range with no clear trend with system velocity. This can be
interpreted as due to density fluctuations on top of a regular R^-2 wind
density profile.Comment: Most figure improved, a few typos corrected, added a new subsection.
ApJ in pres
Immune infiltrating cells in duodenal cancers
Duodenal adenocarcinoma (DA) is a rare yet aggressive malignancy, with increasing incidence in the last decades. Its low frequency has hampered a thorough understanding of the pathogenesis of the disease and of its biology, limiting the identification of tailored therapeutic options. A large body of evidence has clearly shown the clinical relevance of immune cells in solid tumors, correlating immune features with post-surgical prognosis. The aim of this study was to analyze the immune contexture in a cohort of duodenal adenocarcinomas surgically resected at our Institution and define its correlation with clinical variables.
Methods
Tissue slides from paraffin-embedded tumor specimens of 15 consecutive DA and 3 adenomas that underwent a pancreaticoduodenectomy in our center between 2010 to 2018 were immunohistochemically stained. The density (percentage of immune reactive area, IRA%) of immune markers CD45RO, CD8, CD20, IL-17, PD-1, CD68 was quantified by computer-assisted image analysis. Demographic, clinical, histopathological data were collected.
Results
In our population, median IRA % (IQR) of immune subsets was respectively CD45RO-TILs 2.19 (2.14), CD8-TIL 0.42 (0.81), CD20-TILs 0.22 (0.51), CD20-TLT 2.84 (4.64), CD68-TAM 2.19 (1.56), IL17+ cells 0.39 (0.39), PD1-TILs 0.19 (0.41). The median follow-up was 47.5 (22.4\u201363.3) months. At statistical analysis, the density of CD8-TILs inversely correlated with lymph node ratio (p\u2009=\u20090.013), number of metastatic lymph nodes (p\u2009=\u20090.019), and was lower in N+\u2009adenocarcinomas compared to N0 (1.07 vs 0.29; p\u2009=\u20090.093), albeit not significantly. Stratifying patients for the N status, the density of CD8-TILs decreased with the increasing of the N stage (p\u2009=\u20090.065) and was lower in patients who experienced recurrence and died for the disease (0.276 vs 0.641; p\u2009=\u20090.044). Notably, also CD68-TAM distribution was different in patients who had recurrence versus patients who did not (1.028 vs 2.276; p\u2009=\u20090.036).
Conclusions
Immune cells showed variable expression in correlation with common prognostic factors, suggesting T cell infiltration may play a protective role towards lymphatic spread of disease and nodal metastatization. Furthermore, T cell density and macrophage infiltration were associated to a lower risk of recurrence and disease related death. A multicentric approach may be indicated to allow analysis of larger cohorts of patients, potentially increasing the power of our observations
Gamma Doradus Stars: Defining a New Class of Pulsating Variables
In this paper we describe a new class of pulsating stars, the prototype of
which is the bright, early, F-type dwarf, Gamma Doradus. These stars typically
have between 1 and 5 periods ranging from 0.4 to 3 days with photometric
amplitudes up to 0.1 in Johnson V. The mechanism for these observed variations
is high-order, low-degree, non-radial, gravity-mode pulsation. Gamma Doradus
stars exhibit variability on a time scale that is an order of magnitude slower
than Delta Scuti stars. They may offer additional insight into stellar physics
when they are better understood (e.g., they may represent the cool portion of
an "iron opacity instability strip" currently formed by the Beta Cephei stars,
the SPB stars, and the subdwarf B stars; they may also offer insight into the
presence of g-modes in solar-like stars).Comment: 15 pages, 1 ps figure. Accepted for publication in PAS
The outburst of an embedded low-mass YSO in L1641
Strong outbursts in very young and embedded protostars are rare and not yet
fully understood. They are believed to originate from an increase of the mass
accretion rate onto the source. We report the discovery of a strong outburst in
a low-mass embedded young stellar object (YSO), namely 2MASS-J05424848-0816347
or [CTF93]216-2, as well as its photometric and spectroscopic follow-up. Using
near- to mid-IR photometry and NIR low-resolution spectroscopy, we monitor the
outburst, deriving its magnitude, duration, as well as the enhanced accretion
luminosity and mass accretion rate. [CTF93]216-2 increased in brightness by
~4.6, 4.0, 3.8, and 1.9 mag in the J, H, Ks bands and at 24 um, respectively,
corresponding to an L_bol increase of ~20 L_sun. Its early spectrum, probably
taken soon after the outburst, displays a steep almost featureless continuum,
with strong CO band heads and H_2O broad-band absorption features, and Br gamma
line in emission. A later spectrum reveals more absorption features, allowing
us to estimate T_eff~3200 K, M~0.25 M_sun, and mass accretion rate~1.2x10^{-6}
M_sun yr^{-1}. This makes it one of the lowest mass YSOs with a strong outburst
so far discovered.Comment: To be published in A&A letter; 5 pages, 4 figure
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