111 research outputs found
Primary pulmonary melanoma: the unexpected tumour
A 62-year-old woman was referred to our pulmonology team with exertional dyspnoea and chest tightness of 2 months duration. Her medical history included cervical cancer and thyroid nodules. Imaging studies showed collapse of left upper lobe. Fiberoptic bronchoscopy unveiled an endoluminal lesion and bronchial biopsy displayed features of melanoma. She denied a history of melanoma or excision of lesions of skin, mucous membranes or the eye. A thorough evaluation including combined positron emission tomography with CT scan excluded other possible sites of primary melanoma, but there was a metastasis in a thoracic vertebra. Palliative radiotherapy of the spine was performed. Chemotherapy initiation with dacarbazine was postponed by the appearance of a malignant pleural effusion, confirmed by pleural fluid cytology. After four cycles chemotherapy was discontinued due to disease progression. The patient is still alive with a follow-up of 12 months, currently on best supportive care
Receptor chimeras demonstrate that the C-terminal domain of the human cytomegalovirus US27 gene product is necessary and sufficient for intracellular receptor localization
<p>Abstract</p> <p>Background</p> <p>Human cytomegalovirus (HCMV) is ubiquitous in the population but generally causes only mild or asymptomatic infection except in immune suppressed individuals. HCMV employs numerous strategies for manipulating infected cells, including mimicry of G-protein coupled receptors (GPCRs). The HCMV US27 gene product is a putative GPCR, yet no ligand or signaling has been identified for this receptor. In the present study, immunofluorescence microscopy was used to examine the cellular distribution of wild type US27, as well as US27 deletion mutants and chimeric receptors.</p> <p>Results</p> <p>In transiently transfected cells, wild type US27 was found primarily in intracellular compartments, in striking contrast to the cell surface distribution seen for the human cellular chemokine receptor CXCR3. When the N-terminal extracellular domains of the two receptors were swapped, no change in protein localization was observed. However, swapping of the C-terminal intracellular domains resulted in a significant change in receptor distribution. A chimera that contained US27 fused to the C-terminal intracellular tail of CXCR3 exhibited surface distribution similar to that of wild-type CXCR3. When the C-terminal domain of US27 was fused to CXCR3, this chimeric receptor (CXCR3/US27-CT) was found in the same intracellular pattern as wild-type US27. In addition, a US27 mutant lacking the C-terminus (US27ΔCT) failed to accumulate inside the cell and exhibited cell surface distribution. Co-localization with organelle-specific markers revealed that wild-type US27 was found predominantly in the Golgi apparatus and in endosomal compartments, whereas the US27/CXCR3-CT chimera, US27ΔCT and US27Δ348 mutants were not localized to endosomal compartments.</p> <p>Conclusions</p> <p>The results indicate that the C-terminal domain of the HCMV US27 protein, which contains a di-leucine endocytic sorting motif, is both necessary and sufficient for intracellular localization, which may also help explain why no cellular ligands have yet been identified for this viral receptor.</p
The VVV near-IR galaxy catalogue in a Northern part of the Galactic disc
The automated identification of extragalactic objects in large surveys
provides reliable and reproducible samples of galaxies in less time than
procedures involving human interaction. However, regions near the Galactic disc
are more challenging due to the dust extinction. We present the methodology for
the automatic classification of galaxies and non-galaxies at low Galactic
latitude regions using both images and, photometric and morphological near-IR
data from the VVVX survey. Using the VVV-NIRGC, we analyse by statistical
methods the most relevant features for galaxy identification. This catalogue
was used to train a CNN with image data and an XGBoost model with both
photometric and morphological data and then to generate a dataset of
extragalactic candidates. This allows us to derive probability catalogues used
to analyse the completeness and purity as a function of the configuration
parameters and to explore the best combinations of the models. As a test case,
we apply this methodology to the Northern disc region of the VVVX survey,
obtaining 172,396 extragalatic candidates with probabilities of being galaxies.
We analyse the performance of our methodology in the VVV disc, reaching an
F1-score of 0.67, a 65 per cent purity and a 69 per cent completeness. We
present the VVV-NIR Galaxy Catalogue: Northern part of the Galactic disc
comprising 1,003 new galaxies, with probabilities greater than 0.6 for either
model, with visual inspection and with only 2 previously identified galaxies.
In the future, we intend to apply this methodology to other areas of the VVVX
survey.Comment: 12 pages, 14 figures, accepted in MNRA
GW150914: First search for the electromagnetic counterpart of a gravitational-wave event by the TOROS collaboration
We present the results of the optical follow-up conducted by the TOROS
collaboration of the first gravitational-wave event GW150914. We conducted
unfiltered CCD observations (0.35-1 micron) with the 1.5-m telescope at Bosque
Alegre starting ~2.5 days after the alarm. Given our limited field of view
(~100 square arcmin), we targeted 14 nearby galaxies that were observable from
the site and were located within the area of higher localization probability.
We analyzed the observations using two independent implementations of
difference-imaging algorithms, followed by a Random-Forest-based algorithm to
discriminate between real and bogus transients. We did not find any bona fide
transient event in the surveyed area down to a 5-sigma limiting magnitude of
r=21.7 mag (AB). Our result is consistent with the LIGO detection of a binary
black hole merger, for which no electromagnetic counterparts are expected, and
with the expected rates of other astrophysical transients.Comment: ApJ Letters, in pres
Correlación entre las dosis de vancomicina administradas, el clearance de creatinina y la concentración de la vancomicina en plasma en pacientes críticos
La vancomicina (vanco) sufre variaciones en su concentración plasmática (dosaje) según dosis administradas y clearance de creatinina (ClCr), entre otros factores. Varios autores demostraron que dosis fijas de 2 g/día y sin dosis de carga podrían no ser adecuadas para alcanzar dosaje terapéutico de 20-30 mg/L, por aumento (hiperfiltración) o disminución (insuficiencia renal) del ClCr durante el tratamiento, sugiriendo administrar dosis de carga y de mantenimiento, y medir dosajes para ajustar a una dosis efectiva.Facultad de Ciencias Médica
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