Unilateral and segmental localised polycystic kidney disease

Glomerulocystic disease (GCD) is a very rare condition. Only two previous reports have linked this condition with hepatoblastoma. We report a neonate with US evidence of grossly enlarged echogenic kidneys and features typical of hepatic fibrosis, complicated by the presence of a hepatoblastoma. The report discusses the differential diagnosis and highlights GCD as one cause of large, bright kidneys on US. It also adds further evidence to the suggested association between GCD and hepatoblastoma.     

The effect of point mutations on the free energy of transmembrane alpha-helix dimerization

Glycophorin A forms homodimers through interaction of the single, helical transmembrane domains of the monomers. The dimers are stable in sodium dodecylsulfate (SDS), permitting a number of studies that have identified a critical motif of residues that mediates dimer formation. We have used analytical ultracentrifugation to measure the energy of dimerization in a non-denaturing detergent solution and have observed the changes in energy arising from two of the mutants previously studied. Use of the detergent pentaoxyethylene octyl ether (C8E5) is a great advantage, since its micelles are neutrally buoyant and the detergent allows a reversible association to occur between monomer and dimer states of the glycophorin A transmembrane helices during the time-scale of sedimentation equilibrium. Use of this detergent in analytical ultracentrifugation may enable a wide range of studies of molecular association events in membrane proteins. We find that the glycophorin A transmembrane helix dimerizes with a dissociation constant of 240(+/-50) nM, corresponding to a free energy of dissociation of 9.0(+/-0.1) kcal mol-1. Point mutants that were found to be disruptive in SDS (L75A, I76A) reduced the dimer affinity in the C8E5 detergent environment (Kd=1.7(+/-0.2) microM and 4.2(+/-0.9) microM, respectively). Thus, the earlier findings are placed on a quantitative, relative energy scale of association by our measurements. Molecular modeling and simulations suggest that the energy differences can be accounted for as changes in van der Waals interactions between helices.     

Combining tabular, rule-based, and procedural knowledge in computer-based guidelines for childhood immunization

IMM/Serve is a computer program which implements the clinical guidelines for childhood immunization. IMM/Serve accepts as input a child's immunization history. It then indicates which vaccinations are due and which vaccinations should be scheduled next. The clinical guidelines for immunization are quite complex and are modified quite frequently. As a result, it is important that IMM/Serve's knowledge be represented in a format that facilitates the maintenance of that knowledge as the field evolves over time. To achieve this goal, IMM/Serve uses four representations for different parts of its knowledge base: (1) Immunization forecasting parameters that specify the minimum ages and wait-intervals for each dose are stored in tabular form. (2) The clinical logic that determines which set of forecasting parameters applies for a particular patient in each vaccine series is represented using if-then rules. (3) The temporal logic that combines dates, ages, and intervals to calculate recommended dates, is expressed procedurally. (4) The screening logic that checks each previous dose for validity is performed using a decision table that combines minimum ages and wait intervals with a small amount of clinical logic. A knowledge maintenance tool, IMM/Def, has been developed to help maintain the rule-based logic. The paper describes the design of IMM/Serve and the rationale and role of the different forms of knowledge used.     

Perceiving choice and constraint: The effects of contextual and behavioral cues on attitude attribution.

We examined how features of the situation and the target's behavior in the attitude-attribution paradigm may lead observers to infer that the behavior was performed purposefully and how these perceptions may contribute to correspondence bias. Experiment 1 demonstrated that cues suggesting that essay assignment resulted from the target's purposeful action lead to correspondent inferences. When these cues were absent, observers' inferences were not correspondent. Experiment 2 demonstrated that observers are sensitive to cues emitted by the target (facial expressions of delight and disappointment) and that those cues' meaning depends on the context in which they take place. When the essay was freely chosen, the expression had little effect; observers judged that the essay accurately reflected the target's attitudes. When the essay assignment was constrained, observers used the expressions to discount the essay when judging the target's attitudes. We discuss the implications of these findings for the study of correspondent inferences and correspondence bias. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pulsatile stretch in coronary arteries elicits release of endothelium-derived hyperpolarizing factor: a modulator of arterial compliance

We evaluated the effect of ketamine on the excitability of rabbits vagus nerve by measuring evoked compound action potentials. Histological examination was also done by means of electron microscopy on the nerves incubated in ketamine-Ringer's bicarbonate (RB) solution. We found that 0.05% ketamine causes complete suppression of the compound action potentials. The suppressed compound action potentials by incubating in 0.1% ketamine RB solution recovered completely after washing with ketamine-free RB solution. The electron microscopic examinations revealed no histological changes of the nerves incubated in 0.1% ketamine RB solution. We conclude that ketamine suppresses the nerve excitability causing no histological changes at the concentration below 0.1%.     

Dependable, intelligent voting for real-time control software

An intelligent and dependable voting mechanism for use in real-time control applications is presented. Strategies proposed by current safety standards advocate N-version software to minimize the effects of undetected software design faults (bugs). This requires diversity in design but presents a problem in that truly diverse code produces diverse results; that is, differences in output values, timeliness and reliability. Reaching a consensus requires an intelligent voter, especially when non-stop operation is demanded, e.g. in aerospace applications. This paper, therefore, firstly considers the applicable safety standards and the requirements for an intelligent voter service. The use of replicated voters to improve reliability is examined and a mechanism to ensure non-stop operation is presented. The formal mathematical analysis used to verify the crucial behavioural properties of the voting service design is detailed. Finally, the use of neural nets and genetic algorithms to create N- version redundant voters, is considered.