Expectations and violations: Delineating the neural network of proactive inhibitory control

The ability to stop a prepared response (reactive inhibition) appears to depend on the degree to which stopping is expected (proactive inhibition). Functional MRI studies have shown that activation during proactive and reactive inhibition overlaps, suggesting that the whole neural network for reactive inhibition becomes already activated in anticipation of stopping. However, these studies measured proactive inhibition as the effect of stop‐signal probability on activation during go trials. Therefore, activation could reflect expectation of a stop‐signal (evoked by the stop‐signal probability cue), but also violation of this expectation because stop‐signals do not occur on go trials. We addressed this problem, using a stop‐signal task in which the stop‐signal probability cue and the go‐signal were separated in time. Hence, we could separate activation during the cue, reflecting expectation of the stop‐signal, from activation during the go‐signal, reflecting expectation of the stop‐signal or violation of that expectation. During the cue, the striatum, the supplementary motor complex (SMC), and the midbrain activated. During the go‐signal, the right inferior parietal cortex (IPC) and the right inferior frontal cortex (IFC) activated. These findings suggest that the neural network previously associated with proactive inhibition can be subdivided into two components. One component, including the striatum, the SMC, and the midbrain, activated during the cue, implicating this network in proactive inhibition. Another component, consisting of the right IPC and the right IFC, activated during the go‐signal. Rather than being involved in proactive inhibition, this network appears to be involved in processes associated with violation of expectations. Hum Brain Mapp 34:2015–2024, 2013. © 2011 Wiley Periodicals, Inc.     

Return to work after coronary artery bypass surgery. A 10-year follow-up study

Multislice Computed Tomography Coronary Angiography (CTCA) has emerged as a promising non-invasive modality for the detection of coronary artery stenosis. Image quality is still limited when compared to conventional coronary angiography. However, CTCA has been demonstrated to be highly reliable to rule out coronary artery stenosis. Technological improvements and the combination of CTCA with other non-invasive modalities are expected to further increase diagnostic accuracy. Although CTCA has clearly left the research environment, the precise role of CTCA in the diagnostic work-up of coronary artery disease needs further research.     

ASO Visual Abstract: Metastasectomy or Stereotactic Body Radiation Therapy With or Without Systemic Therapy for Oligometastatic Esophagogastric Cancer

Annals of Surgical Oncology -     

Simultaneous Pharmacokinetic Modeling of Gentamicin,Tobramycin and Vancomycin Clearance from Neonates to Adults: Towards a Semi-physiological Function for Maturation in Glomerular Filtration

Purpose

Since glomerular filtration rate (GFR) is responsible for the elimination of a large number of water-soluble drugs, the aim of this study was to develop a semi-physiological function for GFR maturation from neonates to adults.

Methods

In the pharmacokinetic analysis (NONMEM VI) based on data of gentamicin, tobramycin and vancomycin collected in 1,760 patients (age 1 day–18 years, bodyweight 415 g–85 kg), a distinction was made between drug-specific and system-specific information. Since the maturational model for clearance is considered to contain system-specific information on the developmental changes in GFR, one GFR maturational function was derived for all three drugs.

Results

Simultaneous analysis of these three drugs showed that maturation of GFR mediated clearance from preterm neonates to adults was best described by a bodyweight-dependent exponent (BDE) function with an exponent varying from 1.4 in neonates to 1.0 in adults (Cl_GFR?=?Cl_drug*(BW/4 kg)^BDE with BDE?=?2.23*BW^?0.065). Population clearance values (Cl_drug) for gentamicin, tobramycin and vancomycin were 0.21, 0.28 and 0.39 L/h for a full term neonate of 4 kg, respectively.

Discussion

Based on an integrated analysis of gentamicin, tobramycin and vancomycin, a semi-physiological function for GFR mediated clearance was derived that can potentially be used to establish evidence based dosing regimens of renally excreted drugs in children.     

Myocardial perfusion imaging: clinical experience and recent progress in radionuclide scintigraphy and magnetic resonance imaging

In the past 20 years, radionuclide scintigraphy has proven to be a sensitive clinical tool in the assessment of myocardial perfusion abnormalities. Magnetic resonance imaging may also be used to study myocardial perfusion, but its potential value still has to emerge in the clinical setting. This review addresses the potential and achievements of both methods in clinical cardiology.