Atomic data and electron-impact broadening effect in DO white dwarf atmospheres: Si VI

Energy levels, electric dipole transition probabilities and oscillator strengths in five times ionized silicon have been calculated in intermediate coupling. The present calculations were carried out with the general purpose atomic-structure program SUPERSTRUCTURE. The relativistic corrections to the non-relativistic Hamiltonian are taken into account through the Breit-Pauli approximation. We have also introduced a semi-empirical correction (TEC) for the calculation of the energy-levels. These atomic data are used to provide semiclassical electron-, proton- and ionized helium- impact line widths and shifts for 15 Si VI muliplet. Calculated results have been used to consider the influence of Stark broadening for DO white dwarf atmospheric conditions.Comment: MNRAS, accepted, 14 page

On the Magnetic Field Strength of Active Region Filaments

We study the vector magnetic field of a filament observed over a compact Active Region Neutral Line. Spectropolarimetric data acquired with TIP-II (VTT, Tenerife, Spain) of the 10830 \AA spectral region provide full Stokes vectors which were analyzed using three different methods: magnetograph analysis, Milne-Eddington inversions and PCA-based atomic polarization inversions. The inferred magnetic field strengths in the filament are of the order of 600 - 700 G by all these three methods. Longitudinal fields are found in the range of 100 - 200 G whereas the transverse components become dominant, with fields as large as 500 - 600 G. We find strong transverse fields near the Neutral Line also at photospheric levels. Our analysis indicates that strong (higher than 500 G, but below kG) transverse magnetic fields are present in Active Region filaments. This corresponds to the highest field strengths reliably measured in these structures. The profiles of the Helium 10830 \AA lines observed in this Active Region filament are dominated by the Zeeman effect.Comment: Accepted for publication in Astronomy and Astrophysics, 9 pages, 4 figure

Comparing HBV Viral Load in Serum, Cerumen, and Saliva and Correlation With HBeAg Serum Status in Patients With Chronic Hepatitis B Infection

Background: Hepatitis B is a disease that is prevalent worldwide and is responsible for 10 of the deaths that occur every year. The virus persists in 5 of infected adults and 90 of infected children and can cause chronic hepatitis. In addition to blood, the virus may also be present in other secretions. Transmission through saliva, sexual fluids, and urine has also been confirmed. Objectives: The main aim of this study was to compare viral DNA copies in the serum, cerumen, and saliva of patients with HBeAg levels in their sera. Patients and Methods: This was a cross-sectional study and subjects were selected by non-randomized methods. Serum, cerumen, and saliva samples were collected from 50 patients who were diagnosed with chronic hepatitis B about a year prior to the study. Enzyme-linked immunosorbent assay (ELISA) was performed to determine the presence of HBsAg and HBeAg in the gathered specimens. Viral DNA was extracted from specimens by using a Qiagen kit. The number of viral DNA copies was determined using a real-time polymerase chain reaction (PCR) assay. The study was performed in Ilam province in western Iran. Results: Twenty-eight percent of the patients were HBeAg positive. The average number of viral copies in serum, cerumen, and saliva was higher in women than in men, and a significant correlation was observed between the gender and average viral copies. However, no significant correlation was observed between viral copies present in the serum and cerumen with the age and gender of patients. In addition, no correlation was observed between serum HBeAg and viral copies present in serum, cerumen, and saliva. The correlation analysis confirmed a direct and definite correlation between viral DNA loads in the patients' serum and cerumen. Conclusions: A significant direct correlation was observed between the viral DNA copies present in patients' cerumen and serum. However, the correlation between saliva viral load with serum and cerumen viral load was very low and inverse. These findings suggest that the presence of the hepatitis B virus (HBV) in non-invasive specimens (such as cerumen and saliva) should also be evaluated when monitoring patients to determine the course of infection and disease

Gamma-smooth muscle actin expression is associated with epithelial-mesenchymal transition and stem-like properties in hepatocellular carcinoma

BACKGROUND AND AIMS: The prognosis of hepatocellular carcinoma (HCC) is hampered by frequent tumour recurrence and metastases. Epithelial-Mesenchymal Transition (EMT) is now recognized as a key process in tumour invasion, metastasis and the generation of cancer initiating cells. The morphological identification of EMT in tumour samples from the expression of novel mesenchymal markers could provide relevant prognostic information and aid in understanding the metastatic process. METHODS: The expression of Smooth Muscle Actins was studied using immunofluorescence and immunohistochemistry assays in cultured liver cells during an induced EMT process and in liver specimens from adult and paediatric HCC series. RESULTS: We report here that in HCC cell lines treated with TGF-beta and in HCC specimens, the expression of alphaSMA, a known mesenchymal marker of EMT, could never be detected. In addition, our in vitro studies identified the enteric form of SMA, gammaSMA, as being a marker of EMT. Moreover, this SMA isoform was expressed in 46% of 58 tumours from 42 adult HCC patients and in 90% of 16 tumours from 12 paediatric HCC patients. Interestingly, this expression was significantly correlated with poor tumour differentiation and progenitor cell features characterized by the expression of EpCAM and K19. CONCLUSION: Taken together, our results support the conclusion that gammaSMA expression in HCC is strongly correlated with the EMT process, HCC aggressiveness and the identification of cancer stem cells. This correlation suggests that gammaSMA represents a novel and powerful marker to predict HCC progression

Flow cytometric quantification of tumour endothelial cells; an objective alternative for microvessel density assessment

Assessment of microvessel density by immunohistochemical staining is subject to a considerable inter-observer variation, and this has led to variability in correlation between microvessel density and clinical outcome in different studies. In order to improve the method of microvessel density measurement in tumour biopsies, we have developed a rapid, objective and quantitative method using flow cytometry on frozen tissues. Frozen tissue sections of archival tumour material were enzymatically digested. The single-cell suspension was stained for CD31 and CD34 for flow cytometry. The number of endothelial cells was quantified using light scatter- and fluorescence-characteristics. Tumour endothelial cells were detectable in a single cell suspension, and the percentage of endothelial cells detected in 32 colon carcinomas correlated highly (r=0.84, P<0.001) with the immunohistochemical assessment of microvessel density. Flow cytometric endothelial cells quantification was found to be more sensitive especially at lower levels of immunohistochemical microvessel density measurement. The current method was found to be applicable for various tumour types and has the major advantage that it provides a retrospective and quantitative approach to the angiogenic potential of tumours

Protein profiling in hepatocellular carcinoma by label-free quantitative proteomics in two west african populations.

Background Hepatocellular Carcinoma is the third most common cause of cancer related death worldwide, often diagnosed by measuring serum AFP; a poor performance stand-alone biomarker. With the aim of improving on this, our study focuses on plasma proteins identified by Mass Spectrometry in order to investigate and validate differences seen in the respective proteomes of controls and subjects with LC and HCC. Methods Mass Spectrometry analysis using liquid chromatography electro spray ionization quadrupole time-of-flight was conducted on 339 subjects using a pooled expression profiling approach. ELISA assays were performed on four significantly differentially expressed proteins to validate their expression profiles in subjects from the Gambia and a pilot group from Nigeria. Results from this were collated for statistical multiplexing using logistic regression analysis. Results Twenty-six proteins were identified as differentially expressed between the three subject groups. Direct measurements of four; hemopexin, alpha-1-antitrypsin, apolipoprotein A1 and complement component 3 confirmed their change in abundance in LC and HCC versus control patients. These trends were independently replicated in the pilot validation subjects from Nigeria. The statistical multiplexing of these proteins demonstrated performance comparable to or greater than ALT in identifying liver cirrhosis or carcinogenesis. This exercise also proposed preliminary cut offs with achievable sensitivity, specificity and AUC statistics greater than reported AFP averages. Conclusions The validated changes of expression in these proteins have the potential for development into high-performance tests usable in the diagnosis and or monitoring of HCC and LC patients. The identification of sustained expression trends strengthens the suggestion of these four proteins as worthy candidates for further investigation in the context of liver disease. The statistical combinations also provide a novel inroad of analyses able to propose definitive cut-offs and combinations for evaluation of performance

The Reg3alpha (HIP/PAP) Lectin Suppresses Extracellular Oxidative Stress in a Murine Model of Acute Liver Failure

BACKGROUND AND AIMS: Acute liver failure (ALF) is a rapidly progressive heterogeneous illness with high mortality rate and no widely accessible cure. A promising drug candidate according to previous preclinical studies is the Reg3alpha (or HIP/PAP) lectin, which alleviates ALF through its free-radical scavenging activity. Here we study the therapeutic targets of Reg3alpha in order to gain information on the nature of the oxidative stress associated with ALF. METHODS: Primary hepatocytes stressed with the reactive oxygen species (ROS) inducers TNFalpha and H2O2 were incubated with a recombinant Reg3alpha protein. ALF was induced in C57BL/6J mice by an anti-CD95 antibody. Livers and primary hepatocytes were harvested for deoxycholate separation of cellular and extracellular fractions, immunostaining, immunoprecipitation and malondialdehyde assays. Fibrin deposition was studied by immunofluorescence in frozen liver explants from patients with ALF. RESULTS: Fibrin deposition occurs during experimental and clinical acute liver injuries. Reg3alpha bound the resulting transient fibrin network, accumulated in the inflammatory extracellular matrix (ECM), greatly reduced extracellular ROS levels, and improved cell viability. Hepatocyte treatment with ligands of death receptors, e.g. TNFalpha and Fas, resulted in a twofold increase of malondialdehyde (MDA) level in the deoxycholate-insoluble fractions. Reg3alpha treatment maintained MDA at a level similar to control cells and thereby increased hepatocyte survival by 35%. No antioxidant effect of Reg3alpha was noted in the deoxycholate-soluble fractions. Preventing fibrin network formation with heparin suppressed the prosurvival effect of Reg3alpha. CONCLUSIONS: Reg3alpha is an ECM-targeted ROS scavenger that binds the fibrin scaffold resulting from hepatocyte death during ALF. ECM alteration is an important pathogenic factor of ALF and a relevant target for pharmacotherapy