Thrombin-induced events in non-platelet cells are mediated by the unique proteolytic mechanism established for the cloned platelet thrombin receptor.

We recently isolated a cDNA clone encoding a functional platelet thrombin receptor that defined a unique mechanism of receptor activation. Thrombin cleaves its receptor's extracellular amino terminal extension, unmasking a new amino terminus that functions as a tethered peptide ligand and activates the receptor. A novel peptide mimicking this new amino terminus was a full agonist for platelet secretion and aggregation, suggesting that this unusual mechanism accounts for platelet activation by thrombin. Does this mechanism also mediate thrombin's assorted actions on non-platelet cells? We now report that the novel thrombin receptor agonist peptide reproduces thrombin-induced events (specifically, phosphoinositide hydrolysis and mitogenesis) in CCL-39 hamster lung fibroblasts, a naturally thrombin-responsive cell line. Moreover, these thrombin-induced events could be recapitulated in CV-1 cells, normally poorly responsive to thrombin, after transfection with human platelet thrombin receptor cDNA. Our data show that important thrombin-induced cellular events are mediated by the same unusual mechanism of receptor activation in both platelets and fibroblasts, very likely via the same or very similar receptors

Liver Cirrhosis As a Real Risk Factor for Necrotising Fasciitis: a Three-Year Population‑Based Follow‑Up Study

[[abstract]]INTRODUCTION Necrotising fasciitis (NF) is often found in patients with diabetes mellitus, chronic renal failure, alcoholism, malignancy or liver cirrhosis. However, it remains unknown whether liver cirrhosis is an independent risk factor for the occurrence of NF. This study aimed to determine whether liver cirrhosis is an independent risk factor for the occurrence of NF, and to identify the relationship between severity of liver cirrhosis and occurrence of NF. METHODS The National Health Insurance Research Database, maintained by Taiwan’s National Health Insurance programme, was retrospectively analysed, and the hospitalisation data of 40,802 cirrhotic patients and 40,865 randomly selected, age‑ and gender‑matched non‑cirrhotic control patients was collected. The medical records of all patients were individually followed for a three‑year period from the patients’ first hospitalisation in 2004. RESULTS During the three‑year follow‑up period, there were 299 (0.7%) cirrhotic patients with NF and 160 (0.4%) non‑cirrhotic patients with NF. Cox regression analysis showed that liver cirrhosis was a risk factor for the occurrence of NF during the study period (hazard ratio 1.982; p < 0.001). Among cirrhotic patients, those with complicated liver cirrhosis had a higher risk for the occurrence of NF than patients with non‑complicated liver cirrhosis (hazard ratio 1.320; p = 0.028). CONCLUSION Cirrhotic patients had a higher risk for the occurrence of NF than non‑cirrhotic patients, and the risk for NF was especially high among patients with complicated liver cirrhosis.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[booktype]]紙本[[countrycodes]]SG

A new 130nm F.E readout chip for microstrip detectors

In the context of the Silicon tracking for a Linear Collider (SiLC) R&D collaboration, a highly compact mixed-signal chip has been designed in 130nm CMOS technology intended to read Silicon strip detectors for the experiments at the future International Linear Collider. The chip includes eighty eight channels of a full analog signal processing chain and analog to digital conversion with the corresponding digital controls and readout channels. The chip is 5x10mm2 where the analog implementation represents 4/5 of the total Silicon area.Comment: 3 pages, 4 figures, LCWS08 worksho

Differential Effects of Concomitant Use of Vitamins C and E on Trophoblast Apoptosis and Autophagy between Normoxia and Hypoxia-Reoxygenation

Concomitant supplementation of vitamins C and E during pregnancy has been reportedly associated with low birth weight, the premature rupture of membranes and fetal loss or perinatal death in women at risk for preeclampsia; however, the cause is unknown. We surmise that hypoxia-reoxygenation (HR) within the intervillous space due to abnormal placentation is the mechanism and hypothesize that concomitant administration of aforementioned vitamin antioxidants detrimentally affects trophoblast cells during HR.Using villous explants, concomitant administration of 50 microM of vitamins C and E was observed to reduce apoptotic and autophagic changes in the trophoblast layer at normoxia (8% oxygen) but to cause more prominent apoptosis and autophagy during HR. Furthermore, increased levels of Bcl-2 and Bcl-xL in association with a decrease in the autophagy-related protein LC3-II were noted in cytotrophoblastic cells treated with vitamins C and E under standard culture conditions. In contrast, vitamin treatment decreased Bcl-2 and Bcl-xL as well as increased mitochondrial Bak and cytosolic LC3-II in cytotrophoblasts subjected to HR.Our results indicate that concomitant administration of vitamins C and E has differential effects on the changes of apoptosis, autophagy and the expression of Bcl-2 family of proteins in the trophoblasts between normoxia and HR. These changes may probably lead to the impairment of placental function and suboptimal growth of the fetus

Investigating cerebral oedema using poroelasticity

Cerebral oedema can be classified as the tangible swelling produced by expansion of the interstitial fluid volume. Hydrocephalus can be succinctly described as the abnormal accumulation of cerebrospinal fluid (CSF) within the brain which ultimately leads to oedema within specific sites of parenchymal tissue. Using hydrocephalus as a test bed, one is able to account for the necessary mechanisms involved in the interaction between oedema formation and cerebral fluid production, transport and drainage. The current state of knowledge about integrative cerebral dynamics and transport phenomena indicates that poroelastic theory may provide a suitable framework to better understand various diseases. In this work, Multiple-Network Poroelastic Theory (MPET) is used to develop a novel spatio-temporal model of fluid regulation and tissue displacement within the various scales of the cerebral environment. The model is applied through two formats, a one-dimensional finite difference – Computational Fluid Dynamics (CFD) coupling framework, as well as a two-dimensional Finite Element Method (FEM) formulation. These are used to investigate the role of endoscopic fourth ventriculostomy in alleviating oedema formation due to fourth ventricle outlet obstruction (1D coupled model) in addition to observing the capability of the FEM template in capturing important characteristics allied to oedema formation, like for instance in the periventricular region (2D model)

On the extraction of electromagnetic properties of the Delta(1232) excitation from pion photoproduction

Several methods for the treatment of pion photoproduction in the region of the Delta(1232) resonance are discussed, in particular the effective Lagrangian approach and the speed plot analysis are compared to a dynamical treatment. As a main topic, we discuss the extraction of the genuine resonance parts of the magnetic dipole and electric quadrupole multipoles of the electromagnetic excitation of the resonance. To this end, we try to relate the various values for the ratio R_{EM} of the E2 to M1 multipole excitation strengths for the Delta(1232) resonance as extracted by the different methods to corresponding ratios of a dynamical model. Moreover, it is confirmed that all methods for extracting resonance properties suffer from an unitary ambiguity which is due to some phenomenological contributions entering the models.Comment: 22 pages revtex including 7 postscript figure

On the magnetic stability at the surface in strongly correlated electron systems

The stability of ferromagnetism at the surface at finite temperatures is investigated within the strongly correlated Hubbard model on a semi-infinite lattice. Due to the reduced surface coordination number the effective Coulomb correlation is enhanced at the surface compared to the bulk. Therefore, within the well-known Stoner-picture of band ferromagnetism one would expect the magnetic stability at the surface to be enhanced as well. However, by taking electron correlations into account well beyond the Hartree-Fock (Stoner) level we find the opposite behavior: As a function of temperature the magnetization of the surface layer decreases faster than in the bulk. By varying the hopping integral within the surface layer this behavior becomes even more pronounced. A reduced hopping integral at the surface tends to destabilize surface ferromagnetism whereas the magnetic stability gets enhanced by an increased hopping integral. This behavior represents a pure correlation effect and can be understood in terms of general arguments which are based on exact results in the limit of strong Coulomb interaction.Comment: 6 pages, RevTeX, 4 eps figures, accepted (Phys. Rev. B), for related work and info see http://orion.physik.hu-berlin.d

Semiclassical theory of shot-noise suppression

The Boltzmann-Langevin equation is used to relate the shot-noise power of a mesoscopic conductor to classical transmission probabilities at the Fermi level. This semiclassical theory is applied to tunneling through n barriers in series. For n -> infinity the shot noise approaches one third of the Poisson noise, independent of the transparency of the barriers. This confirms that the one-third suppression known to occur in diffusive conductors does not require phase coherence.Comment: pages, RevTeX, 1 figur

High Mortality of Pneumonia in Cirrhotic Patients with Ascites

[[abstract]]Background Cirrhotic patients with ascites are prone to develop various infectious diseases. This study aimed to evaluate the occurrence and effect of major infectious diseases on the mortality of cirrhotic patients with ascites. Methods We reviewed de-identified patient data from the National Health Insurance Database, derived from the Taiwan National Health Insurance Program, to enroll 4,576 cirrhotic patients with ascites, who were discharged from Taiwan hospitals between January 1, 2004 and June 30, 2004. We collected patients’ demographic and clinical data, and reviewed diagnostic codes to determine infectious diseases and comorbid disorders of their hospitalizations. Patients were divided into an infection group and non-infection group and hazard ratios (HR) were determined for specific infectious diseases. Results Of the total 4,576 cirrhotic patients with ascites, 1,294 (28.2%) were diagnosed with infectious diseases during hospitalization. The major infectious diseases were spontaneous bacterial peritonitis (SBP) (645, 49.8%), urinary tract infection (151, 11.7%), and pneumonia (100, 7.7%). After adjusting for patients’ age, gender, and other comorbid disorders, the HRs of infectious diseases for 30-day and 90-day mortality of cirrhotic patients with ascites were 1.81 (1.54-2.11) and 1.60 (1.43-1.80) respectively, compared to those in the non-infection group. The adjusted HRs of pneumonia, urinary tract infection (UTI), spontaneous bacterial peritonitis (SBP), and sepsis without specific focus (SWSF) were 2.95 (2.05-4.25), 1.32 (0.86-2.05), 1.77 (1.45-2.17), and 2.19 (1.62-2.96) for 30-day mortality, and 2.57 (1.93-3.42), 1.36 (1.01-1.82), 1.51 (1.29-1.75), and 2.13 (1.70-2.66) for 90-day mortality, compared to those in the non-infection group. Conclusion Infectious diseases increased 30-day and 90-day mortality of cirrhotic patients with ascites. Among all infectious diseases identified, pneumonia carried the highest risk for mortality.[[notice]]補正完畢[[incitationindex]]SCI[[booktype]]電子

Probing the Rho Spectral Function in Hot and Dense Nuclear Matter by Dileptons

We present a dynamical study of $e^+e^-$ and $\mu^+ \mu^-$ production in proton-nucleus and nucleus-nucleus collisions at CERN-SPS energies on the basis of the covariant transport approach HSD employing a momentum-dependent $\rho$-meson spectral function that includes the pion modifications in the nuclear medium as well as the polarization of the $\rho$-meson due to resonant $\rho$$-N$ scattering. We find that the experimental data from the CERES and HELIOS-3 Collaborations can be described equally well as within the dropping $\rho$-mass scenario. Whereas corresponding dilepton $q_T$-spectra are found to be very similar, the inclusive dilepton yield in the invariant mass range $0.85 \leq M \leq 1.0$ GeV should allow to disentangle the two scenarios experimentally.Comment: 13 pages RevTeX slightly revised, 6 eps-figure