73 research outputs found
MicroRNA-551b expression profile in low and high-grade cervical intraepithelial neoplasia
OBJECTIVE: To evaluate the expression of microRNA (miR)-551b in patients with low and high grade cervical intraepithelial neoplasia (CIN) and to find an association with high-risk Human Papillomavirus (HR-HPV) infection-related prognostic biomarkers.
PATIENTS AND METHODS: The expression level of miR-551b was determined in 50 paraffin-embedded cervical specimens (10 normal squamous epithelium, 18 condylomas, 8 CIN1, and 14 CIN2-3) using quantitative Real-time polymerase chain reaction (qRT-PCR). Ï2-test compared miR-551b expression in different diagnosis groups. An Ordered Logistic Regression and a Probit correlation were made to correlate miR-551b expression levels with the cervical tissue histological findings. The immunohistochemical distribution of p16 and Ki-67 according to histopathological findings was also assessed.
RESULTS: The distribution of the miR-551b expression profile was significantly lower in CIN1-3 samples compared to other histological diagnosis groups (condyloma and negative). The expression levels were inversely correlated to the cervical pathological grade, from negative to CIN2-3. A 1%
increase in miR-551b expression level produced an increase of 19% to the probability of a minor histological grade diagnosis in a range from negative
to CIN2-3 and an increase of 13% to the probability of a negative histological grade diagnosis. Among the cases with miR-551b expression < 0.02
(considered as cut-off value) a significant statistical correlation was found between p16 and Ki-67 expression and the diagnosis of CIN2-3.
CONCLUSIONS: O ur d ata s howed a s ignificant inverse correlation between miR-551b expression and the histological grading of the lesions,
suggesting a tumor suppressive function in the different stages of cervical dysplasia
Updates in Mechanical Thrombectomy
Strokes are a major source of morbidity and mortality worldwide. The long-standing gold standard in stroke therapy, intravenous administration of tissue plasminogen activator (tPA), is limited by strict timing parameters and modest efficacy in large strokes caused by thrombi in the proximal cerebral vasculature. Multiple recent randomized controlled trials have demonstrated the efficacy of mechanical thrombectomy for patients with large vessel occlusions (LVOs). Recent clinical guidelines have been updated to include mechanical thrombectomy as a standard of care in properly selected stroke patients, with ongoing and future studies working to refine the optimal clinical and technical variables of this approach
Dust and gas in luminous infrared galaxies - results from SCUBA observations
We present new data taken at 850 m with SCUBA at the JCMT for a sample
of 19 luminous infrared galaxies. Fourteen galaxies were detected. We have used
these data, together with fluxes at 25, 60 and 100 m from IRAS, to model
the dust emission. We find that the emission from most galaxies can be
described by an optically thin, single temperature dust model with an exponent
of the dust extinction coefficient () of
. A lower is required to model the dust
emission from two of the galaxies, Arp 220 and NGC 4418. We discuss various
possibilities for this difference and conclude that the most likely is a high
dust opacity. In addition, we compare the molecular gas mass derived from the
dust emission, , with the molecular gas mass derived from the CO
emission, , and find that is on average a factor 3 higher than
.Comment: 10 pages, 6 figures, latex, with MN-macros, accepted by MNRAS -
revised version (changed flux values for some galaxies
Young stellar clusters and associations in M33
We analyse multi-wavelength observations of 32 young star clusters and
associations in M33 with known oxygen abundance (8 < 12 + log(O/H) < 8.7),
using ultraviolet (UV), optical, mid-infrared (MIR), CO (1-0) and 21-cm line
(HI) observations. We derive their spectral energy distribution, and we
determine age, bolometric luminosities, masses and the extinction, by comparing
the multi-band integrated photometry to single-age stellar population models.
The stellar system ages range between 2 and 15 Myr, masses are between 3 x 10^2
and 4 x 10^4 M_sun, and the intrinsic extinction, A_V, varies from 0.3 to 1
mag. We find a correlation between age and extinction, and between the cluster
mass and size. The MIR emission shows the presence of a dust component around
the clusters whose fractional luminosity at 24 um, L_{24}/L_{Bol}, decreases
with the galactocentric distance. However, the total IR luminosity inferred
from L_{24} is smaller than what we derive from the extinction corrections. The
Halpha luminosity predicted by population synthesis models is larger than the
observed one, especially for low-mass systems (M < 10^4 M_sun). Such a
difference is reduced, but not erased, when the incomplete sampling of the
initial mass function (IMF) at the high-mass end is taken into account. Our
results suggest that a non-negligible fraction of UV ionising and non-ionising
radiation is leaking into the ISM outside the HII regions. This would be in
agreement with the large UV and Halpha diffuse fractions observed in M33, but
it implies that stellar systems younger than 3 Myr retain, on average, only 30%
of their Lyman continuum photons. However, the uncertainties on cluster ages
and the stochastic fluctuations of the IMF do not allow to accurately quantify
this issue. We also consider the possibility that this discrepancy is the
consequence of a suppressed or delayed formation of the most massive stars.Comment: 17 pages, 13 figures. Accepted for publications in A&A; v2 --> Table
2 corrected because of a misprint in the FUV magnitude
Anomalous Features of EMT during Keratinocyte Transformation
During the evolution of epithelial cancers, cells often lose their characteristic features and acquire a mesenchymal phenotype, in a process known as epithelial-mesenchymal transition (EMT). In the present study we followed early stages of keratinocyte transformation by HPV16, and observed diverse cellular changes, associated with EMT. We compared primary keratinocytes with early and late passages of HF1 cells, a cell line of HPV16-transformed keratinocytes. We have previously shown that during the progression from the normal cells to early HF1 cells, immortalization is acquired, while in the progression to late HF1, cells become anchorage independent. We show here that during the transition from the normal state to late HF1 cells, there is a progressive reduction in cytokeratin expression, desmosome formation, adherens junctions and focal adhesions, ultimately leading to poorly adhesive phenotype, which is associated with anchorage-independence. Surprisingly, unlike âconventional EMTâ, these changes are associated with reduced Rac1-dependent cell migration. We monitored reduced Rac1-dependent migration also in the cervical cancer cell line SiHa. Therefore we can conclude that up to the stage of tumor formation migratory activity is eliminated
Loss of PTEN Is Not Associated with Poor Survival in Newly Diagnosed Glioblastoma Patients of the Temozolomide Era
Introduction: Pre-temozolomide studies demonstrated that loss of the tumor suppressor gene PTEN held independent prognostic significance in GBM patients. We investigated whether loss of PTEN predicted shorter survival in the temozolomide era. The role of PTEN in the PI3K/Akt pathway is also reviewed. Methods: Patients with histologically proven newly diagnosed GBM were identified from a retrospective database between 2007 and 2010. Cox proportional hazards analysis was used to calculate the independent effects of PTEN expression, age
Estereotipia e plasticidade na seqĂŒĂȘncia predatĂłria de Theridion evexum keyserling 1884 (Araneae: Theridiidae)
The evolution of preyâwrapping behaviour in spiders
We traced the evolution of silk use by spiders in attacks on prey by combining previous publications with new observations of 31 species in 16 families. Two new preyâwrapping techniques are described. One, in which the spider holds a tense line (often covered with viscid silk) with both legs IV and applies it to the prey with a simultaneous movement of both legs, may be a synapomorphy linking Theridiidae, Nesticidae, and Synotaxidae. The other, in which the spider stands over the prey and turns in place, is apparently very ancient; it occurs in Theraphosidae, Tengellidae, and Agelenidae. The use of legs IV to wrap prey is described for the first time in Filistatidae and Scytodidae. Using a recent phylogeny of spiders, we propose that prey wrapping with legs IV has evolved convergently at least four times. We propose that prey wrapping originally evolved from eggâsac construction behaviour.Instituto Smithsoniano de Investigaciones Tropicales (STRI)Universidad de Costa RicaUCR::VicerrectorĂa de Docencia::Ciencias BĂĄsicas::Facultad de Ciencias::Escuela de BiologĂ
Lista das espécies de aranhas (Arachnida, Araneae) do estado do Rio Grande do Sul, Brasil
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