Adv Exp Med Biol
-
There are two essential reasons for the slow progress in the acceptance of clinical similarity search-based decision support systems (DSSs); the especial complexity of biomedical data making it difficult to define a meaningful and effective distance function and the lack of transparency and explanation ability in many existing DSSs. In this chapter, we address these two problems by introducing a novel technique for visualizing patient similarity with neighborhood graphs and by considering two techniques for learning discriminative distance functions. We present an experimental study and discuss our implementation of similarity visualization within a clinical DSS.
-
The cerebral tissue oxygenation index (TOI) and fractional tissue oxygen extraction (FTOE) reflect the cerebral oxygenation. We studied the effect of glycaemia on the TOI and FTOE, as measured by near-infrared-spectroscopy (NIRS). ⋯ We found a significant negative correlation (r = -0.077; p = 0.0344) between glycaemia and TOI, also after correction for MABP, SaO(2) and tPCO(2) (r = -0.118; p = 0.002) and a significant positive correlation between glycaemia and FTOE (r = 0.147; p < 0.000) which remained significant after correction for MABP and tPCO(2) (r = 0.116; p = 0.001). Our results indicate that in neonates during the first days of life glycaemia - even within the normal ranges and after correction for MABP, SaO(2) and tPCO(2) - influences the cerebral oxygenation.
-
Sepsis is an infectious condition that results in damage to organs. This paper proposes a severe sepsis model based on Support Vector Machine (SVM) for predicting whether a septic patient will become severe sepsis. ⋯ The results show that the prognosis of a septic patient can be more precisely predicted than ever. We conduct several experiments, whose results demonstrate that the proposed model provides high accuracy and high sensitivity and can be used as a reminding system to provide in-time treatment in ICU.
-
Sensory gating is the brain's ability to adjust its sensitivity to incoming stimuli, i.e., to diminish its response to irrelevant or repetitive stimuli (gating out) and to increase it when a novel stimulus is presented (gating in). Most of the existing studies have investigated the gating out mechanism, giving little attention to the gating in function. Although both the P50 and N100 components of the auditory ERPs (event related potentials) show amplitude reductions to stimuli repetition, it is not clear if both components are part of a common gating system or if their sensory modulation is uncorrelated. ⋯ Thus, the results showed that both P50 and N100 are sensory modulated, showing that amplitude decreased to stimuli repetition (gating out) and increased when the two stimuli of a pair differed in intensity (gating in). A correlational analysis of the sensory gating indices (S2/S1 ratio and S1-S2 difference) obtained for P50 and N100 suggested that the sensory gating function of both components may be of a different nature. The reliability of the ratio and the difference indices of sensory gating is also discussed.
-
We recently reported that volatile anaesthetics directly depress the isolated glomus cell response to hypoxia, halothane more so than sevoflurane, in a manner mimicking the action of these agents on the human hypoxic ventilatory response. We wished to extend these investigations to action of another agent (isoflurane), and we planned to examine the effects of this agent and halothane on background K(+) channels. In an isolated rat pup glomus cell preparation intracellular calcium [Ca(2+)]i (measured using indo-1 dye), halothane and isoflurane (0.45-2.73 MAC) depressed the Ca(2+) transient response to hypoxia (p = 0.028), halothane more than isoflurane (p < 0.001). ⋯ When glomus cells were exposed to a depolarising stimulus using 100 mM K(+), both halothane and isoflurane modestly reduced the magnitude of the resulting Ca(2+) transient (by 44% and 10% respectively, p < 0.001). We conclude that the effect of volatile anaesthetics on the glomus cell response to hypoxia is mediated at least in part by their effect on background K(+) channels, and that this plausibly explains their whole-body effect. An additional effect on voltage-gated Ca(2+) is also possible.