Biomedical subjects

Marta Soler

Publications and source records attributed to Marta Soler.

6 recordsLinked to original sources

PubMed2006

Ultrasonographic, computed tomographic and magnetic resonance imaging anatomy of the normal canine stifle joint.

Ultrasonographic (US), magnetic resonance (MR) and computed tomographic (CT) images of normal canine stifle joints were obtained and compared with plastinated cross-sectional slices of cadaver specimens from the same dogs. The bony and articular structures were identified and correlated with the three diagnostic imaging modalities. These results provide an atlas of normal cross-sectional US, MR and CT anatomy of the canine stifle, which can be used for the interpretation of stifle images from any of these imaging modalities.

Anatomy, Cross-Sectional↗

PubMed2006

The RING finger protein RNF8 recruits UBC13 for lysine 63-based self polyubiquitylation.

The heterodimeric ubiquitin conjugating enzyme (E2) UBC13-UEV mediates polyubiquitylation through lysine 63 of ubiquitin (K63), rather than lysine 48 (K48). This modification does not target proteins for proteasome-dependent degradation. Searching for potential regulators of this variant polyubiquitylation we have identified four proteins, namely RNF8, KIA00675, KF1, and ZNRF2, that interact with UBC13 through their RING finger domains. These domains can recruit, in addition to UBC13, other E2s that mediate canonical (K48) polyubiquitylation. None of these RING finger proteins were known previously to recruit UBC13. For one of these proteins, RNF8, we show its activity as a ubiquitin ligase that elongates chains through either K48 or K63 of ubiquitin, and its nuclear co-localization with UBC13. Thus, our screening reveals new potential regulators of non-canonical polyubiquitylation.

Amino Acid Sequence↗

PubMed2005

Dual activation of pathways regulated by steroid receptors and peptide growth factors in primary prostate cancer revealed by Factor Analysis of microarray data.

BACKGROUND: We use an approach based on Factor Analysis to analyze datasets generated for transcriptional profiling. The method groups samples into biologically relevant categories, and enables the identification of genes and pathways most significantly associated to each phenotypic group, while allowing for the participation of a given gene in more than one cluster. Genes assigned to each cluster are used for the detection of pathways predominantly activated in that cluster by finding statistically significant associated GO terms. We tested the approach with a published dataset of microarray experiments in yeast. Upon validation with the yeast dataset, we applied the technique to a prostate cancer dataset. RESULTS: Two major pathways are shown to be activated in organ-confined, non-metastatic prostate cancer: those regulated by the androgen receptor and by receptor tyrosine kinases. A number of gene markers (HER3, IQGAP2 and POR1) highlighted by the software and related to the later pathway have been validated experimentally a posteriori on independent samples. CONCLUSION: Using a new microarray analysis tool followed by a posteriori experimental validation of the results, we have confirmed several putative markers of malignancy associated with peptide growth factor signalling in prostate cancer and revealed others, most notably ERRB3 (HER3). Our study suggest that, in primary prostate cancer, HER3, together or not with HER4, rather than in receptor complexes involving HER2, could play an important role in the biology of these tumors. These results provide new evidence for the role of receptor tyrosine kinases in the establishment and progression of prostate cancer.

Biomarkers, Tumor↗

PubMed2005

Paraffin-embedded cell line microarray (PECLIMA): development and validation of a high-throughput method for antigen profiling of cell lines.

The introduction of high-throughput techniques is increasingly providing abundant information on molecular alterations requiring validation at the posttranscriptional level. Protein expression is now efficiently evaluated in large series of tumors included in tissue microarrays. We propose, describe and validate a technique to elaborate paraffin-embedded cell line microarrays (PECLIMA) from fixed cell cultures, which can be processed like standard surgical pathology biopsies prior to immunophenotyping. Our results show a reliable protein immunoexpression profiling in six widely used cell lines under different fixation conditions. This technique permits the simultaneous analysis of multiple antigens in multiple cell lines under different experimental conditions. Additional features of these arrays are long-term storage, their suitability for a variety of techniques including immunocytochemistry and in situ hybridization and their low cost.

Antigens, Neoplasm↗

PubMed2004

Modification of prostanoid secretion in endothelial cells by amphotericin B acting synergistically with interleukin-1beta: possible explanation of proinflammatory effects.

Human umbilical vein endothelial cells were exposed to free-form and lipid-complexed versions of amphotericin B (alone or in combination with human recombinant interleukin [IL]-1 beta) and to culture medium from the human macrophage cell line THP-1 that had been exposed to amphotericin B. Endothelial cells were then incubated with exogenous-labeled arachidonic acid or were stimulated with histamine. Measurement of the resulting prostanoids indicated that amphotericin B and IL-1 beta acted synergistically to increase the ability of endothelial cells to synthesize prostanoids from endogenous and exogenous substrate and to increase expression of cyclooxygenase-2. This resulted in an increase of the ratio of untransformed prostaglandin (PG) H2 to PGI2 released by endothelial cells. Culture medium from amphotericin B-activated macrophages caused similar effects in endothelial cells. The synergistic effect with IL-1 beta was observed with free-form amphotericin B and, to a lesser extent, with lipid-complexed amphotericin B (Abelcet). Differences between Abelcet and the lipisome carrier (AmBisome) were not significantly different with respect to any of the parameters analyzed.

Amphotericin B↗

PubMed2003

Imidazolineoxyl N-oxide prevents the impairment of vascular contraction caused by interleukin-1beta through several mechanisms.

Overnight exposure to interleukin (IL)-1beta caused a dramatic hyporesponsiveness to phenylephrine, increased nitric oxide (NO) and prostacyclin production, and induced cycloxygenase-2 expression in rat aortic rings. Using different inhibitors, we found that this hyporeactivity was mediated by NO, prostacyclin, and activation of charybdotoxin-sensitive K(+) channels. The latter was independent of the presence of endothelium and NO and prostanoid synthesis during the challenge with phenylephrine. Activation of charybdotoxin-sensitive K(+) channels was probably due to NO stores formed during the exposition to IL-1beta; 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), either when added with IL-1beta or in the organ bath, partially restored the contractility of IL-1beta-treated vessels. The cPTIO effect was mimicked by combinations of cyclooxygenase and NO-synthase inhibitors and by charybdotoxin. cPTIO significantly inhibited prostacyclin formation and prostacyclin-synthase activity during incubation with the cytokine. cPTIO antagonized the effect of IL-1beta by scavenging NO, reducing prostacyclin-synthase activity, and avoiding the contribution activation of K(+) channels.

Animals↗