Pre-Liver Transplant: Tips Versus Distal Splenorenal Shunt

Recurrent variceal bleeding in liver transplant candidates with end-stage liver disease can complicate or even prohibit a subsequent transplant procedure (OLT). Endoscopic sclero-therapy and medical therapy are considered as first-line management with surgical shunts reserved for refractory situations. Surgical shunts can be associated with a high mortality in this population and may complicate subsequent OLT. The transjugular intrahepatic portosystemic shunt (TIPS) has been recommended in these patients as a bridge to OLT. This is a new modality that has not been compared with previously established therapies such as the distal splenorenal shunt (DSRS). In this study we report our experience with 35 liver transplant recipients who had a previous TIPS (18 patients) or DSRS (17 patients) for variceal bleeding. The TIPS group had a significantly larger proportion of critically ill and Child-Pugh C patients. Mean operating time was more prolonged in the DSRS group (P=0.014) but transfusion requirements were similar. Intraoperative portal vein blood flow measurements averaged 2132±725 ml/min in the TIPS group compared with 1120±351ml/min in the DSRS group (P<0.001). Arterial flows were similar. Mean ICU and hospital stays were similar. There were 3 hospital mortalities in the DSRS group and none in the TIPS group (P=0.1). We conclude that TIPS is a valuable tool in the management of recurrent variceal bleeding prior to liver transplantation. Intra0Perative hemodynamic measurements suggest a theoretical advantage with TIPS. In a group of patients with advanced liver disease we report an outcome that is similar to patients treated with DSRS prior to liver transplantation. The role of TIPS in the treatment of nontransplant candidates remains to be clarified

Relaxation rate of the reverse biased asymmetric exclusion process

We compute the exact relaxation rate of the partially asymmetric exclusion process with open boundaries, with boundary rates opposing the preferred direction of flow in the bulk. This reverse bias introduces a length scale in the system, at which we find a crossover between exponential and algebraic relaxation on the coexistence line. Our results follow from a careful analysis of the Bethe ansatz root structure.Comment: 22 pages, 12 figure

Evidence for Parton kT Effects in High pT Particle Production

Inclusive pizero and direct-photon cross sections in the kinematic range 3.5 < pT < 12 GeV/c with central rapidities are presented for 530 and 800 GeV/c proton beams and a 515 GeV/c pi- beam incident on beryllium targets. Current Next-to-Leading-Order perturbative QCD calculations fail to adequately describe the data for conventional choices of scales. Kinematic distributions from these hard scattering events provide evidence that the interacting partons carry significant initial-state parton transverse momentum (kT). Incorporating these kT effects phenomenologically greatly improves the agreement between calculations and the measured cross sections.Comment: 11 pages including 6 pages of figures with caption

UV Circular Polarisation in Star Formation Regions : The Origin of Homochirality?

Ultraviolet circularly polarised light has been suggested as the initial cause of the homochirality of organic molecules in terrestrial organisms, via enantiomeric selection of prebiotic molecules by asymmetric photolysis. We present a theoretical investigation of mechanisms by which ultraviolet circular polarisation may be produced in star formation regions. In the scenarios considered here, light scattering produces only a small percentage of net circular polarisation at any point in space, due to the forward throwing nature of the phase function in the ultraviolet. By contrast, dichroic extinction can produce a fairly high percentage of net circular polarisation (∼10%) and may therefore play a key role in producing an enantiomeric excessPeer reviewe

Measurement of direct photon production at Tevatron fixed target energies

Measurements of the production of high transverse momentum direct photons by a 515 GeV/c piminus beam and 530 and 800 GeV/c proton beams in interactions with beryllium and hydrogen targets are presented. The data span the kinematic ranges of 3.5 < p_T < 12 GeV/c in transverse momentum and 1.5 units in rapidity. The inclusive direct-photon cross sections are compared with next-to-leading-order perturbative QCD calculations and expectations based on a phenomenological parton-k_T model.Comment: RevTeX4, 23 pages, 32 figures, submitted to Phys. Rev.

What can be learned from phenotyping and genotyping analyses of Scedosporium prolificans isolates from diverse origins?

Introduction: Scedosporium prolificans is a filamentous fungus considered as an emerging opportunistic member of the order Microascaceae. This fungus has a broad clinical spectrum and can cause different types of infections: localized colonization in immunocompetent hosts or disseminated mycosis in immunocompromised patients. Moreover, S. prolificans resistance to most antifungal agents has been reported. Compared to the well characterized Scedosporium / Pseudallescheria complex, little is known about the fundamental aspects of S. prolificans biology, pathogenicity and epidemiology. Aim of the study: Our goal was to characterize a large population of S. prolificans strains, isolated from animals, human, or environment samples in different countries (European, USA and Australia). Results &amp; methods: All strains were prospectively collected, and grown at 30# C on Sabouraud’s agar medium with kanamycin for 1 week. DNA was extracted from subcultures using UltraClean Fecal# DNA kit (MoBio, France). To improve the knowledge of this species at the phylogenetic level, we combined phenotypic criteria such as macroscopic and microscopic morphology features, antifungal susceptibilities based on E-test# method, and genotypic characterization using multi-loci approaches (superoxide dismutase, beta-tubulin and internal transcript spacer genes). Phylogenetic trees were constructed with unambiguously CLUSTALW aligned sequences using the neighbour-joining method with Kimura-2 parameter as substitution model and maximum parsimony analysis, using the BioEdit version 7.0.0 and Phylip version 2.0 softwares. Discussion: Among our collection composed of 59 isolates, we identified three macroscopically different morphotypes of S. prolificans and some genetic polymorphisms (1.8–2.2% difference between the analyzed sequences). These low sequence polymorphisms reflected intra-specific genetic variations. Therefore, we hypothesized that S. prolificans might be stable in space, and apparently insensitive to xenical or environmental factors. No correlation between clinical-biological characteristics and genotypic or phenotypic criteria of S. prolificans strains was found. In conclusion, our results supported the current perception of S. prolificans as a unique species and an emerging opportunistic pathogen

Production of pizero and eta mesons at large transverse momenta in pi-p and pi-Be interactions at 515 GeV/c

We present results on the production of high transverse momentum pizero and eta mesons in pi-p and pi-Be interactions at 515 GeV/c. The data span the kinematic ranges 1 < p_T < 11 GeV/c in transverse momentum and -0.75 < y < 0.75 in rapidity. The inclusive pizero cross sections are compared with next-to-leading order QCD calculations and to expectations based on a phenomenological parton-k_T model.Comment: RevTeX4, 15 pages, 15 figures, to be submitted to Phys. Rev.

Zinc Finger Recombinases with Adaptable DNA Sequence Specificity

Site-specific recombinases have become essential tools in genetics and molecular biology for the precise excision or integration of DNA sequences. However, their utility is currently limited to circumstances where the sites recognized by the recombinase enzyme have been introduced into the DNA being manipulated, or natural ‘pseudosites’ are already present. Many new applications would become feasible if recombinase activity could be targeted to chosen sequences in natural genomic DNA. Here we demonstrate efficient site-specific recombination at several sequences taken from a 1.9 kilobasepair locus of biotechnological interest (in the bovine β-casein gene), mediated by zinc finger recombinases (ZFRs), chimaeric enzymes with linked zinc finger (DNA recognition) and recombinase (catalytic) domains. In the "Z-sites" tested here, 22 bp casein gene sequences are flanked by 9 bp motifs recognized by zinc finger domains. Asymmetric Z-sites were recombined by the concomitant action of two ZFRs with different zinc finger DNA-binding specificities, and could be recombined with a heterologous site in the presence of a third recombinase. Our results show that engineered ZFRs may be designed to promote site-specific recombination at many natural DNA sequences