High-output congestive heart failure following transjugular intrahepatic portal-systemic shunting

A hyperdynamic circulatory state with elevated cardiac output, decreased peripheral vascular resistance, and sodium retention occurs in patients with portal cirrhosis. Surgical portal-systemic shunts and transjugular intrahepatic portal-systemic shunts (TIPS) have been shown to worsen the high-output state in these patients. However, clinical evidence of high-output congestive heart failure has been reported only rarely to complicate cirrhosis. We describe a patient who developed high-output congestive heart failure with markedly elevated filling pressures after TIPS and had complete resolution of heart failure after liver transplantation.     

A genetic analysis of aromatic amino acid hydroxylases involvement in DOPA synthesis during Drosophila adult development

This study was designed to examine whether cyclosporine (CyA) acts on the endocrine system by modifying the pulsatile secretion pattern of prolactin and LH. Both pituitary-grafted and sham-operated rats were submitted to a subcutaneous vehicle or CyA (5 mg/kg) treatment daily for 10 days beginning on the day of surgery. Pituitary grafting and/or CyA administration changed the pulsatile pattern of prolactin observed in sham-operated animals. The mean values of serum prolactin were significantly increased by pituitary grafting and the treatment with CyA further increased them. The mean half-life of prolactin was significantly increased in pituitary-grafted rats and was not changed by CyA administration, although it was decreased in sham-operated rats. The frequency of prolactin pulses was significantly decreased in pituitary-grafted as compared to sham-operated controls and was not further modified by CyA administration. However, in sham-operated rats a significant decrease of this parameter was observed. Duration of the prolactin peaks was significantly increased by pituitary grafting, and was not modified by CyA administration in any of the groups studied. The absolute amplitude of the prolactin peaks was significantly increased in pituitary-grafted as compared to sham-operated animals, and the treatment with CyA further increased this parameter in both groups. Mean values of LH were significantly increased in pituitary-grafted as compared to control rats. CyA administration significantly increased LH levels in sham-operated rats and decreased them in pituitary-grafted animals. The mean half-life, the pulse frequency and the duration of LH peaks were not modified by either pituitary grafting or CyA administration.(ABSTRACT TRUNCATED AT 250 WORDS)     

Integration of data systems and technology improves research and collaboration for a superfund research center

Large collaborative centers are a common model for accomplishing integrated environmental health research. These centers often include various types of scientific domains (e.g., chemistry, biology, bioinformatics) that are integrated to solve some of the nation's key economic or public health concerns. The Superfund Research Center (SRP) at Oregon State University (OSU) is one such center established in 2008 to study the emerging health risks of polycyclic aromatic hydrocarbons while using new technologies both in the field and laboratory. With outside collaboration at remote institutions, success for the center as a whole depends on the ability to effectively integrate data across all research projects and support cores. Therefore, the OSU SRP center developed a system that integrates environmental monitoring data with analytical chemistry data and downstream bioinformatics and statistics to enable complete "source-to-outcome" data modeling and information management. This article describes the development of this integrated information management system that includes commercial software for operational laboratory management and sample management in addition to open-source custom-built software for bioinformatics and experimental data management.     

Loss of precious metal from Pt-Rh alloy under refractory oxide environments

Loss of precious metals from a Pt-10 wt% Rh alloy was studied at 1300° C in refractory oxides and fused quartz environments. After 60 and 150 h annealings, samples exposed to gaseous environments showed significant weight loss. The surface was attacked and characterized by micron-sized pits, as well as river-like striations. The pits were found to be enriched with silicon and/or aluminium depending upon the heating environment. Laser Raman microprobe identified that the major compound formed in the pits is -cristobalite.Direct solid state contact of Pt-Rh with Al₂O₃ and SiO₂ showed interactions between materials. The interaction was more extensive between Pt-Rh with SiO₂ than with Al₂O₃. On the other hand, no evidence of interaction except pitting and striation was observed on Pt-Rh when exposed to a vapour environment.The presence of pits and striation patterns indicated that refractory oxides attacked Pt-Rh under atmospheric conditions, and gave rise to the weight loss. Calculation of weight loss by an oxidation mechanism shows one to two orders of magnitude lower value than the actual weight loss. A new loss mechanism is proposed and discussed in this article.     

Characterising the energy deposition events produced by trapped protons in low earth orbit

Men and equipment in space vehicles in low earth orbit are exposed to a wide variety of radiations, but the majority of the dose is due to trapped protons, which have energies of the order of 100 MeV and are low LET particles. These high energy particles produce nuclear fragmentation with high LET secondaries that may be responsible for a significant fraction of dose equivalent. In order to understand better the biological effectiveness of this radiation environment, a portable tissue equivalent proportional counter spectrometer has been developed that automatically records the distribution of energy in a small tissue-like site as a function of time. This instrument weighs about 700 g and will be flown on a number of future space shuttle flights.     

Specific heat at constant flux density for a low-κ type II superconductor

The specific heat at constant flux densityC _B was measured to study the thermodynamic properties of the mixed state of a type II superconductor at low reduced temperaturet=T/T _c . The sample was a Pb_0.96Tl_0.04 alloy having =0.97. The results are thatC _B increases nearly linearly withB throughout the mixed state, with a discontinuous jump down to the normal state value at the upper critical field. Att<0.21 a small, positive curvature ofC _B versusB is consistent with Eilenberger's calculations. However, this positive curvature is not consistent with fluxoid interaction models for low flux density. These measurements supplement previous measurements fort<0.5 using isothermal calorimetry on the same sample. Taken together, the two experiments indicate that, at a givenT, the incremental entropy per fluxoid is nearly constant for allB. This result forces some interesting empirical relationships among the parameters that characterize the mixed state.On sabbatical leave from South Dakota School of Mines and Technology, Rapid City, South Dakota.     

Hysteresis effects with ZrO2 oxygen sensors exposed to non-equilibrium oxygen-hydrocarbon mixtures

Hysteresis effects are reported for ZrO₂ oxygen sensors exposed to non-equilibrium oxygen/hydrocarbon gas mixtures. With oxygen/toluene at 800° C, voltage-composition curves differ following composition changes (a) from excess oxygen to excess toluene and (b) from excess toluene to excess oxygen. A catalysis model is developed to account for this behaviour: the Thiele modulus of the catalyst/electrode is presumed to differ under (a) net oxidizing and (b) net reducing conditions. Large scale voltage fluctuations, sometimes exceeding 400 mV, were observed in experiments with oxygen/isobutane mixtures at 600° C. This behaviour is analysed in terms of a kinetic model involving stochastic variations of relative mass transfer coefficients of oxygen and isobutane.