Renal effects of a urodilatin infusion in patients with liver cirrhosis, with and without ascites

This study reports the effects of a short-term (60 min) low-dose (20 ng x kg(-1) x min(-1)) infusion of synthetic urodilatin (URO) in patients with liver cirrhosis. URO is a natriuretic peptide. A total of 15 cirrhotic patients with ascites and nine without ascites participated in a randomized, double-blind, placebo-controlled study in a crossover design. Renal hemodynamics were estimated by a clearance technique using radioactive tracers, and tubular handling of sodium was evaluated by the lithium clearance method. The renal effects of URO were characterized by a significant increase in urine sodium excretion rate (UNa) and urine flow rate (V) in the cirrhotic patients without ascites (UNa: 173%; V: 94%) and with ascites (UNa: 219%, P < 0.01; V: 42%, P < 0.01) when compared with placebo infusions. Fractional excretion of sodium increased significantly, indicating a tubular effect of URO on sodium handling. Filtration fraction, lithium clearance (a marker of end-proximal fluid delivery), and fractional excretion of lithium increased, fractional proximal tubular sodium reabsorption decreased, and absolute proximal tubular sodium reabsorption remained unchanged, suggesting increased delivery of isotonic fluid from the proximal tubule during URO infusion. In addition, a significant decrease in fractional distal tubular sodium reabsorption contributed to the natriuresis. In conclusion, URO improved sodium and urine output in cirrhotic patients with and without ascites by enhancing fluid delivery from the proximal tubules in addition to inhibiting fractional sodium reabsorption in the distal nephron.     

Leptin in human reproduction: serum leptin levels in pregnant and lactating women

Experiments in ob/ob female mice demonstrated that leptin injections not only reduced weight and fat mass, but also restored fertility and partial lactation. To explore factors regulating ob gene expression in reproductive women, we measured serum leptin, body fat, energy expenditure, and milk production in 65 women at 36 weeks of gestation, and at 3 and 6 months postpartum. Serum leptin was measured by solid-phase sandwich enzyme immunoassay, and serum insulin and PRL by solid-phase 125I RIA. Total body water by deuterium dilution, body volume by hydrodensitometry, and bone density by dual-energy x-ray absorptiometry were used to estimate body fat. Serum leptin per unit fat mass was significantly higher at 36 weeks of pregnancy than at 3 and 6 months postpartum (1.25 vs. 0.75, 0.73 ng.mL-1.kg-1). Postpartum normalization of leptin was associated with changes not only in weight and fat mass, but also serum insulin. Leptin was not different between lactating and nonlactating women. Leptin may have affected milk production indirectly through its negative effect on serum PRL. Adjusted for fat-free mass and fat mass, rates of energy expenditure were not significantly correlated with leptin. Our results provide evidence that factors other than fat mass alone modulate serum leptin in reproductive women.     

Dobutamine stress echocardiography for assessing coronary artery disease after transplantation in children

OBJECTIVES: The purpose of this study was to determine the feasibility, safety and diagnostic accuracy of dobutamine stress echocardiography (DSE) for evaluating posttransplant coronary artery disease (TxCAD) in children, and to determine the frequency of selected cardiac events after normal or abnormal DSE. BACKGROUND: Posttransplant coronary artery disease is the most common cause of graft loss (late death or retransplantation) after cardiac transplantation (CTx) in children. Coronary angiography, routinely performed to screen for TxCAD, is an invasive procedure with limited sensitivity. The efficacy of DSE for detecting atherosclerotic coronary artery disease is established, but is unknown in children after CTx. METHODS: Of the 78 children (median age 5.7 years, range 3 to 18) entered into the study, 72 (92%) underwent diagnostic DSE by means of a standard protocol, 4.6 +/- 1.9 years after CTx. The results of coronary angiography performed in 70 patients were compared with DSE findings. After DSE, subjects were monitored for TxCAD-related cardiac events, including death, retransplantation and new angiographic diagnosis of TxCAD. RESULTS: No major complications occurred. Minor complications, most often hypertension, occurred in 11% of the 72 subjects. The sensitivity and specificity of DSE were 72% and 80%, respectively, when compared with coronary angiography. At follow-up (21 +/- 8 months), TxCAD-related cardiac events occurred in 2 of 50 children (4%) with negative DSE, versus 6 of 22 children (27%) with positive DSE (p < 0.01). CONCLUSIONS: DSE is a feasible, safe and accurate screening method for TxCAD in children. Positive DSE identifies patients at increased risk of TxCAD-related cardiac events. Negative DSE predicts short-term freedom from such events.     

Age changes in processing speed as a leading indicator of cognitive aging.

Bivariate dual change score models were applied to longitudinal data from the Swedish Adoption/Twin Study of Aging to compare the dynamic predictions of 2-component theories of intelligence and the processing speed theory of cognitive aging. Data from up to 5 measurement occasions covering a 16-year period were available from 806 participants ranging in age from 50 to 88 years at the first measurement wave. Factors were generated to tap 4 general cognitive domains: verbal ability, spatial ability, memory, and processing speed. Model fitting indicated no dynamic relationship between verbal and spatial factors, providing no support for the hypothesis that age changes in fluid abilities drive age changes in crystallized abilities. The results suggest that, as predicted by the processing speed theory of cognitive aging, processing speed is a leading indicator of age changes in memory and spatial ability, but not verbal ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Iron,Nitrogen Co-Doped Carbon Spheres as Low Cost,Scalable Electrocatalysts for the Oxygen Reduction Reaction

Atomically dispersed transition metal-nitrogen-carbon catalysts are emerging as low-cost electrocatalysts for the oxygen reduction reaction in fuel cells. However, a cost-effective and scalable synthesis strategy for these catalysts is still required, as well as a greater understanding of their mechanisms. Herein, iron, nitrogen co-doped carbon spheres (Fe@NCS) have been prepared via hydrothermal carbonization and high-temperature post carbonization. It is determined that FeN₄ is the main form of iron existing in the obtained Fe@NCS. Two different precursors containing Fe²⁺ and Fe³⁺ are compared. Both chemical and structural differences have been observed in catalysts starting from Fe²⁺ and Fe³⁺ precursors. Fe²⁺@NCS-A (starting with Fe²⁺ precursor) shows better catalytic activity for the oxygen reduction reaction. This catalyst is studied in an anion exchange membrane fuel cell. The high open-circuit voltage demonstrates the potential approach for developing high-performance, low-cost fuel cell catalysts.     

Emissions of ultrafine particles from five types of candles during steady burn conditions

Emissions from candles are of concern for indoor air quality. In this work, five different types of pillar candles were burned under steady burn conditions in a new laboratory scale system for repeatable and controlled comparison of candle emissions (temperature ~25°C, relative humidity ~13%, O₂ >18%, air exchange rate 1.9 h⁻¹). Burn rate, particle number concentrations, mass concentrations, and mode diameters varied between candle types. Based on the results, the burning period was divided in two phases: initial (0–1 h) and stable (1–6 h). Burn rates were in the range 4.4–7.3 and 4.7–7.1 g/h during initial and stable phase, respectively. Relative particle number emissions, mode diameters, and mass concentrations were higher during the initial phase compared to the stable phase for a majority of the candles. We hypothesize that this is due to elevated emissions of wick additives upon ignition of the candle together with a slightly higher burn rate in the initial phase. Experiments at higher relative humidity (~40%) gave similar results with a tendency toward larger particle sizes at the higher relative humidity. Chemical composition with respect to inorganic salts was similar in the emitted particles (dry conditions) compared to the candlewicks, but with variations between different candles.     

Optimization of ordered plasmid assembly by gap repair in Saccharomyces cerevisiae

Combinatorial genetic libraries are powerful tools for diversifying and optimizing biomolecules. The process of library assembly is a major limiting factor for library complexity and quality. Gap repair by homologous recombination in Saccharomyces cerevisiae can facilitate in vivo assembly of DNA fragments sharing short patches of sequence homology, thereby supporting generation of high‐complexity libraries without compromising fidelity. In this study, we have optimized the ordered assembly of three DNA fragments into a gapped vector by in vivo homologous recombination. Assembly is achieved by co‐transformation of the DNA fragments and the gapped vector, using a modified lithium acetate protocol. The optimal gap‐repair efficiency is found at a 1:80 molar ratio of gapped vector to each of the three fragments. We measured gap‐repair efficiency in different genetic backgrounds and observed increased efficiency in mutants carrying a deletion of the SGS1 helicase‐encoding gene. Using our experimental conditions, a gap‐repair efficiency of > 10⁶ plasmid‐harbouring colonies/µg gapped vector DNA is obtained in a single transformation, with a recombination fidelity > 90%. Copyright © 2012 John Wiley & Sons, Ltd.     

A quantitative approach towards a better understanding of the dynamics of Salmonella spp. in a pork slaughter-line

Pork contributes significantly to the public health disease burden caused by Salmonella infections. During the slaughter process pig carcasses can become contaminated with Salmonella. Contamination at the slaughter-line is initiated by pigs carrying Salmonella on their skin or in their faeces. Another contamination route could be resident flora present on the slaughter equipment. To unravel the contribution of these two potential sources of Salmonella a quantitative study was conducted. Process equipment (belly openers and carcass splitters), faeces and carcasses (skin and cutting surfaces) along the slaughter-line were sampled at 11 sampling days spanning a period of 4 months. Most samples taken directly after killing were positive for Salmonella. On 96.6% of the skin samples Salmonella was identified, whereas a lower number of animals tested positive in their rectum (62.5%). The prevalence of Salmonella clearly declined on the carcasses at the re-work station, either on the cut section or on the skin of the carcass or both (35.9%). Throughout the sampling period of the slaughter-line the total number of Salmonella per animal was almost 2 log lower at the re-work station in comparison to directly after slaughter. Seven different serovars were identified during the study with S. Derby (41%) and S. Typhimurium (29%) as the most prominent types. A recurring S. Rissen contamination of one of the carcass splitters indicated the presence of an endemic 'house flora' in the slaughterhouse studied. On many instances several serotypes per individual sample were found. The enumeration of Salmonella and the genotyping data gave unique insight in the dynamics of transmission of this pathogen in a slaughter-line. The data of the presented study support the hypothesis that resident flora on slaughter equipment was a relevant source for contamination of pork.     

Bread from common cereal cultivars contains an important array of neglected bioactive benzoxazinoids

Bread is consumed in large quantities all over the world, and rye bread is especially popular throughout the Nordic countries. Wholemeal bread is highly recommended as a basic ingredient in daily food, because wholemeal food products generally promote good health due to their vitamin, mineral and fibre content. The literature suggests that wholemeal products have other health-promoting effects even if the ingredients responsible have not been identified. Benzoxazinoids are a group of natural products that have not previously been reported in mature grains. Here, we report for the first time the identity and quantity of 10 compounds of the benzoxazinoid family in mature grains, hydrothermally processed grains of durum wheat (Triticum durum, cv. Kamut), a commercial variety of rye (Secale cereale cv. Picasso) and an old Nordic rye landrace (S. cereale, Svedjerug), as well as in bread baked with flour milled from those grains. Concentrations of the 10 benzoxanoids were determined using LC–MS/MS and ranged from 0 to 348 nmol g⁻¹ for conventional flour, to 772–1177 nmol g⁻¹ in bread baked with flour from hydrothermally processed grains and to 3116–5570 nmol g⁻¹ in flour from hydrothermally processed grains. Benzoxazinoids possess documented physiological effects, and research into the importance of these compounds in the daily diet is therefore needed. Ongoing studies in our lab on the uptake and transformation of benzoxazinoids in mammals will be reported in the near future.     

A Framework for Planning a Unified Wired and Wireless ICT Infrastructure

The increase in the use of information and communication technology (ICT) has pushed the existing access networks to their limits. Whole new access networks are currently being deployed and are expected to fully support the already started synergy of services converging on to one network. Through a brief survey of synergy and technology trends, it is concluded that a future network will use wired and wireless as complementary technologies. In this context the paper proposes a framework for planning of unified wired and wireless ICT infrastructures. The framework includes different input parameters of relevance for the planning and implementation, which also include a step-wise implementation plan. Planning methods for wired and wireless planning is presented and a simplified large-scale case study is conducted to verify and illustrate the use of the framework. The framework is concluded to be useful and the discussion lists some areas for further consideration.