1,143 research outputs found
Effectiveness of antimicrobial-coated sutures for the prevention of surgical site infection: a review of the literature
OBJECTIVE:Surgical site infections (SSIs) are the third most common hospital-acquired infections and account for 14% to 16% of all such infections, and suture material may play a role in SSI rate. Given this risk of infection, sutures with antimicrobial activity have been developed. Both in vitro and in vivo experiments have shown that triclosan-coated sutures (TCS) are effective in the prevention of SSIs. Our aim is to analyze currently available RCTs, comparing the effect of antimicrobial-coated suture (ACS) with uncoated suture on the occurrence of SSIs following surgical procedures, we highlighted major contributions of most significant studies and evaluate the current "state of the art" on antimicrobial-coated sutures.MATERIALS AND METHODS: We reviewed 15 RCTs comparing antimicrobial-coated sutures with conventional sutures and assessing the clinical effectiveness of antimicrobial sutures to decrease the risk for SSIs. We focused our attention on each variable in all the analyzed study. RESULTS:Our selected RCTs, produced controversial results: 7 RCTs demonstrated a significant benefit, on the contrary, 8 RCTs presented a comparison in which there was no difference.CONCLUSIONS:On the basis of our selected trial results and the heterogeneous findings of our 7 selected meta-analyses, we conclude that even though the question of whether TCSs could reduce the occurrence of SSI remains still open, the antimicrobial suture was effective in decreasing the risk for postoperative SSIs in a broad population of patients undergoing surgery. Alternative substances are becoming clinically relevant, such as Chlorhexidine (CHX) coated sutures and only 6 in vivo scientific studies evaluated them. In vivo studies, large and comparative clinical research trials are necessary to validate the efficacy of CHX-coated sutures thus allowing their use in clinical practice
Iginio Tansini revisited
The origin of the muscolocutaneous latissimus dorsi flap dates back to 1906 when Igino Tansini, an Italian surgeon, described a procedure to reconstruct the mastectomy defect. After a detailed study of Tansini's original description and drawings, new insights about the pedicle of its compound flap have been found, showing that it has the same pedicle of the scapular flap. In the end, Tansini's flap should be more correctly considered as a compound musculocutaneous scapular flap
Iginio Tansini revisited
The origin of the muscolocutaneous latissimus dorsi flap dates back to 1906 when Igino Tansini, an Italian surgeon, described a procedure to reconstruct the mastectomy defect. After a detailed study of Tansini's original description and drawings, new insights about the pedicle of its compound flap have been found, showing that it has the same pedicle of the scapular flap. In the end, Tansini's flap should be more correctly considered as a compound musculocutaneous scapular flap
Bright OB stars in the Galaxy.II. Wind variability in O supergiants as traced by H-alpha
We investigate the line-profile variability (lpv) of H-alpha for a large
sample of O-type supergiants. We used the Temporal Variance Spectrum (TVS)
analysis, developed by Fullerton et al 1996 and modified by us to take into
account the effects of wind emission. By means of a comparative analysis we put
a number of constraints on the properties of the variability as a function of
stellar and wind parameters. The results of our analysis show that all the
stars in the sample show evidence of significant lpv in H-alpha, mostly
dominated by processes in the wind. The variations occur between zero and 0.3
v_inf (i.e., below ~1.5 R_star), in good agreement with the results from
similar studies. A comparison between observations and line-profile simulations
indicates that for stars with intermediate wind densities the H-alpha
variability can be explained by simple models, consisting of coherent or broken
shells (blobs) uniformly distributed over the wind volume, with an intrinsic
scatter in the maximum density contrast of about a factor of two. For stars at
lower and higher wind densities, on the other hand, we found certain
inconsistencies between observations and our predictions, most importantly
concerning the mean amplitude and the symmetry properties of the TVS. This
disagreement might be explained with the presence of coherent large-scale
structures, partly confined in a volume close to the star. Interpreted in terms
of a variable mass-loss rate, the observed variations of H-alpha indicate
changes of 4% with respect to the mean value of M_dot for stars with stronger
winds and of 16% for stars with weaker winds. The effect of these variations on
the corresponding wind momenta is rather insignificant (<0.16 dex), increasing
the local scatter without affecting the Wind Momentum Luminosity Relationship.Comment: 22 pages, 11 figures. Accepted by Astronomy and Astrophysic
Isolated, Massive Supergiants near the Galactic Center
We have carried out a pilot project to assess the feasibility of using radio,
infrared, and X-ray emission to identify young, massive stars located between 1
and 25 pc from the Galactic center. We first compared catalogs compiled from
the Very Large Array, the Chandra X-ray Observatory, and 2MASS. We identified
two massive, young stars: the previously-identified star that is associated
with the radio HII region H2, and a newly-identified star that we refer to as
CXOGC J174516.1-290315. The infrared spectra of both stars exhibit very strong
Br-gamma and He I lines, and resemble those of massive supergiants that have
evolved off of the main sequence, but not yet reached the Wolf-Rayet phase. We
estimate that each star has a bolometric luminosity >10^6 L_sun. The detection
of these two sources in X-rays is surprising, because stars at similar
evolutionary states are not uniformly bright X-ray sources. Therefore, we
suggest that both stars are in binary systems that contain either OB stars
whose winds collide with those of the luminous supergiants, or compact objects
that are accreting from the winds of the supergiants. We also identify X-ray
emission from a nitrogen-type Wolf-Rayet star and place upper limits on the
X-ray luminosities of three more evolved, massive stars that previously have
been identified between 1 and 25 pc from Sgr A*. Finally, we briefly discuss
the implications that future searches for young stars will have for our
understanding of the recent history of star formation near the Galactic center.
(abridged)Comment: 9 pages, including 8 figures. Submitted to ApJ, and modified in
response to referee's repor
GIANO-TNG spectroscopy of red supergiants in the young star cluster RSGC3
The Scutum complex in the inner disk of the Galaxy has a number of young star
clusters dominated by red supergiants that are heavily obscured by dust
extinction and observable only at infrared wavelengths. These clusters are
important tracers of the recent star formation and chemical enrichment history
in the inner Galaxy. During the technical commissioning and as a first science
verification of the GIANO spectrograph at the Telescopio Nazionale Galileo, we
secured high-resolution (R=50,000) near-infrared spectra of five red
supergiants in the young Scutum cluster RSGC3. Taking advantage of the full
YJHK spectral coverage of GIANO in a single exposure, we were able to measure
several tens of atomic and molecular lines that were suitable for determining
chemical abundances. By means of spectral synthesis and line equivalent width
measurements, we obtained abundances of Fe and iron-peak elements such as Ni,
Cr, and Cu, alpha (O, Mg, Si, Ca, Ti), other light elements (C, N, F, Na, Al,
and Sc), and some s-process elements (Y, Sr). We found average half-solar iron
abundances and solar-scaled [X/Fe] abundance patterns for most of the elements,
consistent with a thin-disk chemistry. We found depletion of [C/Fe] and
enhancement of [N/Fe], consistent with standard CN burning, and low 12C/13C
abundance ratios (between 9 and 11), which require extra-mixing processes in
the stellar interiors during the post-main sequence evolution. We also found
local standard of rest V(LSR)=106 km/s and heliocentric V(HEL)=90 km/s radial
velocities with a dispersion of 2.3 km/s. The inferred radial velocities,
abundances, and abundance patterns of RSGC3 are very similar to those
previously measured in the other two young clusters of the Scutum complex,
RSGC1 and RSGC2, suggesting a common kinematics and chemistry within the Scutum
complex
Lines and continuum sky emission in the near infrared: observational constraints from deep high spectral resolution spectra with GIANO-TNG
Aims Determining the intensity of lines and continuum airglow emission in the
H-band is important for the design of faint-object infrared spectrographs.
Existing spectra at low/medium resolution cannot disentangle the true
sky-continuum from instrumental effects (e.g. diffuse light in the wings of
strong lines). We aim to obtain, for the first time, a high resolution infrared
spectrum deep enough to set significant constraints on the continuum emission
between the lines in the H-band. Methods During the second commissioning run of
the GIANO high-resolution infrared spectrograph at La Palma Observatory, we
pointed the instrument directly to the sky and obtained a deep spectrum that
extends from 0.97 to 2.4 micron. Results The spectrum shows about 1500 emission
lines, a factor of two more than in previous works. Of these, 80% are
identified as OH transitions; half of these are from highly excited molecules
(hot-OH component) that are not included in the OH airglow emission models
normally used for astronomical applications. The other lines are attributable
to O2 or unidentified. Several of the faint lines are in spectral regions that
were previously believed to be free of line emission. The continuum in the
H-band is marginally detected at a level of about 300
photons/m^2/s/arcsec^2/micron, equivalent to 20.1 AB-mag/arcsec^2. The observed
spectrum and the list of observed sky-lines are published in electronic format.
Conclusions Our measurements indicate that the sky continuum in the H-band
could be even darker than previously believed. However, the myriad of airglow
emission lines severely limits the spectral ranges where very low background
can be effectively achieved with low/medium resolution spectrographs. We
identify a few spectral bands that could still remain quite dark at the
resolving power foreseen for VLT-MOONS (R ~6,600).Comment: 7 pages, 4 figures, to be published in Astronomy & Astrophysic
Prognostic significance of tyrosinase expression in sentinel lymph node biopsy for ultra-thin, thin, and thick melanomas
Abstract. – BACKGROUND: Investigate if the tyrosinase mRNA expression may be predictive of the outcome on ultra-thin, thin, and thick melanoma patients.
AIM: In our study, we sought to correlate tyrosinase mRNA expression to the outcome in a group of 71 patients with thick, thin and ultra-thin melanomas.
MATERIALS AND METHODS: 71 patients with melanomas underwent a SLNB (sentinel lymph node biopsy) at the “Sapienza” University of Rome. Among these, 38 patients had thin melanomas, while the other 33 patients had thick melanomas. In every patient’s sample histology, immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR) was completed. We then correlated tyrosinase mRNA expression to the statistical analysis of the outcome of patients.
RESULTS: Positivity of histology was found in one patient (1.4%), immunohistochemistry in five patients (7%), and tyrosinase in 52/71 (73.2%). Thickness and tyrosinase positivity were predictive for disease progression (p < 0.05). The median follow-up was 58.24 months. There were recurrences and/or deaths in both groups of patients.
CONCLUSIONS: Nodal metastasis in melanoma is uncommon, especially in patients with thin melanomas. In this study, histology and immunohistochemistry were found to be non predictive
for the risk of nodal metastases, while instead, tyrosinase m-RNA expression appeared to play a role in highlighting those patients with a risk of disease progression. Moreover, no differences
among the thin melanoma groups of patients (0.30-0.75 mm and 0.76-1.00 mm) were observed
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