Characterisation of a candidate dual AGN

We present Chandra and optical observations of a candidate dual AGN discovered serendipitously while searching for recoiling black holes via a cross-correlation between the serendipitous XMM source catalog (2XMMi) and SDSS-DR7 galaxies with a separation no larger than ten times the sum of their Petrosian radii. The system has a stellar mass ratio M$_{1}$/M$_{2}\approx 0.7$. One of the galaxies (Source 1) shows clear evidence for AGN activity in the form of hard X-ray emission and optical emission-line diagnostics typical of AGN ionisation. The nucleus of the other galaxy (Source 2) has a soft X-ray spectrum, bluer colours, and optical emission line ratios dominated by stellar photoionisation with a "composite" signature, which might indicate the presence of a weak AGN. When plotted on a diagram with X-ray luminosity vs [OIII] luminosity both nuclei fall within the locus defined by local Seyfert galaxies. From the optical spectrum we estimate the electron densities finding n$_{1} < 27$ e$^{-}$ cm$^{-3}$ and n$_{2} \approx 200$ e$^{-}$ cm$^{-3}$. From a 2D decomposition of the surface brightness distribution we infer that both galaxies host rotationally supported bulges (Sersic index $< 1$). While the active nature of Source 1 can be established with confidence, whether the nucleus of Source 2 is active remains a matter of debate. Evidence that a faint AGN might reside in its nucleus is, however, tantalising.Comment: 16 pages, 9 figures. Accepted for publication on MNRAS. Comments welcom

Decrease of apoptosis rate in patients with renal transplantation treated with mycophenolate mofetil

We conclude that treatment with MMF of kidney transplant patients does not affect the proliferative rate of cells of the allograft, but decreases the number of apoptotic cells in tubular epithelium

Investigation of wear mechanics and behaviour of NiCr metallic foam abradables

Current aero-engine sealing materials are reaching their operating limit, as manufacturers seek more efficient engines with longer service lives. Even when utilised in optimum conditions, current materials have inconsistencies in performance due to variabilities in their microstructure, which lead to undesirable responses and events. As such, a new generation of sealing materials is required. Metallic foams are one such material, given the opportunities that exist to both engineer material properties, and achieve relatively consistent microstructures when compared to the current class of thermally sprayed abradable materials. In this study, the abradability of a nickel (70%)–chromium (30%) (NiCr) alloy foam is investigated, with the role of cell size and filler material considered. Tests are performed on a representative high-speed test rig, where a flat blade is used to simulate an aero-engine incursion event. A series of in situ measurement techniques, such as force, temperature and stroboscopic wear measurements are used to characterise the incursion, with DIC (Digital Image Correlation) techniques also employed to investigate breakdown of the foam. Unfilled foams were shown to lead to high blade wear, with the inclusion of filler materials leading to load transfer and collapse of the foam away from the incursion site, along with improved fracture. Both load transfer and ligament collapse mechanisms were found to promote more favourable rub mechanics at all incursion rates tested

Toward the biochemical assessment of myocardial fibrosis in hypertensive patients

The serum concentrations of amino-terminal procollagen type III and carboxy-terminal procollagen type I-derived peptides, which have been proposed as useful markers of the tissue synthesis of collagen types III and type I, respectively, were abnormally increased in patients with essential hypertension and became normal after angiotensin-converting enzyme (ACE) inhibition. An association was found between baseline serum concentrations of these peptides and left ventricular hypertrophy, diastolic dysfunction, and ventricular arrhythmias in hypertensive patients. On the other hand, increased serum concentration of the carboxy-terminal procollagen type I-derived peptide was found in spontaneously hypertensive rats compared with normotensive Wistar-Kyoto control rats. An association was found between the serum concentration of this peptide and the extent of myocardial fibrosis and the hydroxyproline concentration in the left ventricle of spontaneously hypertensive rats. It is proposed that procollagen-derived peptides in serum may be markers of exaggerated collagen tissue synthesis involved in hypertensive myocardial fibrosis

Emergence of Secondary Acute Leukemia in a Patient Treated for Osteosarcoma: Implications of Germline TP53 Mutations

Secondary leukemia and myelodysplastic syndromes have been reported in patients following treatment for a wide range of neoplastic disorders. However second malignancies after chemotherapy and/or irradiation for osteosarcoma are unusual. PROCEDURE: We report the case of a 15-year-old girl who developed a myelodysplastic syndrome with evolution to acute nonlymphocytic leukemia after treatment for osteosarcoma. Therapy-related acute leukemia karyotype findings such as abnormalities of chromosomes 5, 7, and 17 were found in the cytogenetic analysis. Moreover, using denaturing gradient gel electrophoresis and DNA sequencing, we detected the presence of a double germline mutation in exon 7 of the TP53 gene. CONCLUSION: This observation supports the possibility of a causal relationship between germline TP53 mutations and the development of secondary leukemia and myelodysplasi

Biología molecular del carcinoma de tiroides de estirpe folicular. Bases moleculares en la oncogénesis tiroidea

Existen datos que nos permiten afirmar que probablemente, en gran parte de los casos, no existe una solución de continuidad entre las diferentes neoplasias tiroideas de estirpe folicular. Cabe pensar que el proceso evolutivo comienza con una serie de alteraciones moleculares que condicionan la aparición del adenoma folicular (AF). Cambios posteriores propiciarán el desarrollo de un carcinoma folicular (CF). La aparición del carcinoma papilar (CP) tiene probablemente un itinerario similar sin que esté demostrado que tenga su origen en AF. Ulteriores cambios genéticos, tanto en el CP como en el CF encaminarán hacia la indiferenciación celular y con ello el desarrollo del carcinoma indiferenciado (CI). Esta sucesión de alteraciones moleculares condiciona un empeoramiento en el pronóstico de la neoplasia tiroidea. Por ello, las neoplasias tiroideas constituyen un excelente modelo para el estudio de la cronología de los cambios moleculares que condicionan la evolución desde la benignidad a la malignidad. Se ha comprobado que en algunas neoplasias de tiroides existe inestabilidad genética que favorece dichos cambios moleculares. Como fenómeno inicial es frecuente observar alteraciones en los protooncogenes mientras que las mutaciones en los genes supresores de tumor suelen ser un evento tardío. La aparición de agresividad o invasividad de la neoplasia también se puede investigar mediante el estudio de cambios moleculares. La aplicación clínica de dichos hallazgos comienza a ser una realidad, lo que facilitará la precisión diagnóstica y con ello una terapéutica más eficaz.According to current data, it seems probable that there is no interruption in the evolution of different follicular thyroid neoplasm. Probably transforming events responsible for the transition from normal to tumor cells start with molecular changes that determine the appearance of follicular adenoma. Later changes propitiate the development of follicular cancer. It is likely that the generation of papillary carcinoma follows a different pathway without passing through a previous phase of follicular adenoma. Subsequently, genetic changes render the cell prone to a failure to differentiate, culminating in the development of anaplastic cancer. Those incidental molecular changes result in a dramatic worsening in the prognosis of thyroid cancer. Research into thyroid tumors is likely to be instructive in view of the spectrum they span, from benign adenomas to poorly differentiated carcinomas. It has been proven that molecular alterations in thyroid tumor cells are predisposed by genome instability. Usually changes of protooncogenes represent an early event whereas mutations of suppressant genes are usually a late phenomenon. The onset of aggressive or invasive behavior may be studied, and perhaps can be predicted in the future, by molecular changes. The clinical application of the growing understanding of gene alterations involved in thyroidal oncogenesis is becoming a reality. Such knowledge might contribute, in the near future, to greater diagnostic accuracy and effective treatment for thyroid malignancie

Pathological and virological findings in patients with persistent hypertransaminasaemia of unknown aetiology

BACKGROUND: The histopathological spectrum and role of hepatitis viruses in cases of hypertransaminasaemia of unknown aetiology have not been correctly analysed in a sufficiently large number of patients. METHODS: We studied 1075 consecutive patients referred for liver biopsy because of elevation of alanine aminotransferase (ALT) levels for more than six months. From this population we selected those cases in whom the aetiology could not be defined from clinical, biochemical, and serological data obtained before biopsy. In these patients liver biopsies were reviewed, and hepatitis B virus (HBV)-DNA and hepatitis C virus (HCV)-RNA were assayed in serum by polymerase chain reaction (PCR). Serum hepatitis G virus (HGV)-RNA was determined by PCR in 74 patients. RESULTS: Of 1075 patients studied, the cause of the increased serum ALT levels remained elusive after appropriate testing in 109 patients (10.1%). Liver biopsies from these patients showed non-specific changes in 32.7% of cases, non-alcoholic steatohepatitis (NASH) in 15.8%, and chronic hepatitis or cirrhosis in 51.5%. HBV-DNA and/or HCV-RNA was detected more frequently in cryptogenic liver disease than in healthy blood donors (26.7% v 3.4%; p<0.001). HGV-RNA was found in only one patient. The proportion of cases with detectable HBV-DNA or HCV-RNA was 14.3% in patients with non-specific changes or NASH, 30.7% in patients with chronic hepatitis, and 61.5% in patients with cirrhosis. Cirrhosis was found more frequently in patients with positive HBV-DNA and/or HCV-RNA in serum than in those who tested negatively (p=0.005). CONCLUSIONS: In our series, patients in whom biochemical and serological data did not determine the aetiology of the disease represented 10% of all cases referred for liver biopsy for persistent elevation of serum transaminases. Approximately 50% of patients had chronic hepatitis or cirrhosis and the remainder had NASH or non-specific changes. Occult viral infections were found in a high proportion of cases in the first group and in a low percentage of patients in the second