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Activity pacing (AP) is a concept that is central to many chronic pain theories and treatments, yet there remains confusion regarding its definition and effects.To review the current knowledge concerning AP and integrate this knowledge in a manner that allows for a clear definition and useful directions for future research.A narrative review of the major theoretical approaches to AP and of the empirical evidence regarding the effects of AP interventions, followed by an integrative discussion.The concept of AP is derived from 2 main traditions: operant and energy conservation. Although there are common elements across these traditions, significant conceptual and practical differences exist, which has led to confusion. Little empirical evidence exists concerning the efficacy of AP as a treatment for chronic pain.Future research on AP should be based on a clear theoretical foundation, consider the context in which the AP behavior occurs and the type of pacing problem ("underactivity" vs. "overactivity"), and should examine the impact of AP treatment on multiple clinical outcomes. We provide a provisional definition of AP and specific recommendations that we believe will move the field forward.

The hollow-fibre oxygenator is a key component of any extracorporeal circuit used to provide cardiopulmonary bypass (CPB) during open-heart surgery. Since the oxygenator is placed downstream of the pump, the energy losses over it have a direct impact on the quality of pulsatile pressure and flow waveforms. The objective of this study was to describe the effects of hydrodynamic characteristics of the oxygenator on energy transfer during pulsatile, normothermic CPB. Twenty-three adult patients scheduled for coronary bypass surgery were divided randomly into two groups, using either an oxygenator (Group 1) with a relatively high-resistance and low-compliance (2079 ± 148 dyn.s.cm-5 and 0.00348 ± 0.00071 ml.mmHg-1, respectively) or an oxygenator (Group 2) with a relatively low-resistance and high-compliance (884 ± 464 dyn.s.cm-5 and 0.01325 ± 0.00161 ml .mmHg-1, respectively). During perfusion, pre- and post-oxygenator pressures, radial artery pressure, and blood flow were recorded simultaneously. A 32% decline of mean pressure was observed in Group 1 and a 16% decline in Group 2 (p<0.0001). Another decrease by approximately 73% in mean pressure in the rest of the perfusion system was noted in both groups. The mean radial artery pressure did not differ between the groups (74 ± 6 mmHg in Group 1 and 73 ± 6 mmHg in Group 2, p=0.608). Although lower total energy transfer indices were noticed through the low-resistance oxygenator (Group 2), both oxygenators showed a decrease of the generated pump oscillatory energy of approximately 50%. Despite the differences in resistance and compliance of the hollow-fibre oxygenators used, both oxygenators cause a comparable loss of generated oscillatory energy. Exclusion of the oxygenator downstream of the pulsatile pump would improve energy transfer during CPB.

Recent evidence from animal research and in vitro experiments indicates that changes in dietary calcium intake could cause changes in lipolysis through alterations of the intracellular calcium concentration in adipocytes. The objective of the study was to examine whether the calcium antagonist hydralazine affects blood flow and lipolysis in subcutaneous abdominal adipose tissue in vivo in humans. Three different concentrations of hydralazine (12.2, 24.4, and 48.8 micromol/L) were locally administered in adipose tissue using the microdialysis technique to assess effects on lipolysis and blood flow in subcutaneous adipose tissue in the abdominal region. Subjects from the general community were studied ambulatorily at a university hospital. Eight healthy men (age, 33.1 +/- 3.3 years; body mass index, 24.2 +/- 0.2 kg/m(2)) were recruited by local announcement. Subcutaneous adipose tissue in the abdominal region was perfused with increasing concentrations of hydralazine. The main outcome measures were adipose tissue lipolysis and blood flow. Hydralazine had no effect on ethanol outflow-inflow ratios, but significantly increased interstitial glycerol concentration at the highest concentration (P < .05). The present results indicate that hydralazine increases lipolysis in abdominal subcutaneous adipose tissue in healthy lean subjects, but hydralazine had no significant effects on local blood flow in adipose tissue.

China has achieved impressive rapid economic growth over the past 30 years but accompanied by significant extreme weather events and environmental changes caused by global change and overfast urbanization. Using the absolute hazards index (AHI), we assessed the spatial distribution patterns and related health effects of 4 major extreme natural disasters, including drought, floods (landslides, mudslides), hails, and typhoons from 2000 to 2011 at the provincial level in China. The results showed that (1) central and south China were the most affected by the 4 natural disasters, and north China suffered less; (2) the provinces with higher AHI suffered most from total death, missing people, collapse, and emergently relocated population; (3) the present health emergency response system to disasters in China mainly lacks a multidisciplinary approach. In the concluding section of this article, suggestions on preparedness and rapid response to extreme health events from environmental changes are proposed.

A 53‐year‐old female patient with hypertrophic obstructive cardiomyopathy (HOCM) was admitted for alcohol septal ablation (ASA). A subcutaneous internal cardioverter defibrillator (S‐ICD) was implanted for primary prevention. After ASA, the patient developed a right bundle branch block, and the S‐ICD delivered a total of five inappropriate shocks due to T‐wave oversensing (TWOS). TWOS is a relatively frequent cause of inappropriate shocks in S‐ICD patients. After invasive treatment for HOCM, there is a risk of developing intraventricular conduction delay and subsequent changes in QRS and T‐wave morphology. This should be taken into consideration when ICD indication is evaluated in HOCM patients.

Various spinal cord stimulation (SCS) modes are used in the treatment of chronic neuropathic pain disorders. Conventional (Con) and Burst-SCS are hypothesized to exert analgesic effects through different stimulation-induced mechanisms. Preclinical electrophysiological findings suggest that stimulation intensity is correlated with the effectiveness of Burst-SCS. Therefore, we aimed to investigate the relation between amplitude (charge per second) and behavioral effects in a rat model of chronic neuropathic pain, for both Conventional Spinal Cord Stimulation (Con-SCS) and biphasic Burst-SCS.Animals (n = 12 rats) received a unilateral partial sciatic nerve ligation, after which they were implanted with quadripolar electrodes in the epidural space at thoracic level 13. Mechanical hypersensitivity was assessed using paw withdrawal thresholds (WTs) to von Frey monofilaments, at various SCS intensities (amplitudes) and multiple time points during 60 minutes of stimulation and 30 minutes post stimulation.Increasing amplitude was shown to improve the efficacy of Con-SCS, whereas the efficacy of Burst-SCS showed a non-monotonic relation with amplitude. Con-SCS at 66% MT (n = 5) and Burst-SCS at 50% MT (n = 6) were found to be equally effective in normalizing mechanical hypersensitivity. However, in the assessed time period Burst-SCS required significantly more mean charge per second to do so (p < 0.01). When applied at comparable mean charge per second, Con-SCS resulted in a superior behavioral outcome (p < 0.01), compared with Burst-SCS.Biphasic Burst-SCS requires significantly more mean charge per second in order to achieve similar pain relief, as compared with Con-SCS, in an experimental model of chronic neuropathic pain.

Cannabis is not only the most widely used illicit drug worldwide but is also regularly consumed along with ethanol. In previous studies, it was assumed that cannabis users develop cross-tolerance to ethanol effects. The present study was designed to compare the effects of ethanol in comparison to and in combination with a cannabis joint and investigate changes in pharmacokinetics. In this study, 19 heavy cannabis users participated and received three alcohol dosing conditions that were calculated to achieve steady blood alcohol concentrations (BAC) of about 0, 0.5 and 0.7 g/l during a 5-h time window. Subjects smoked a Δ(9)-tetrahydrocannabinol (THC) cigarette (400 μg/kg) 3 h post-onset of alcohol dosing. Blood samples were taken between 0 and 4 h after smoking. During the first hour, samples were collected every 15 min and every 30 min thereafter. Mean steady-state BACs reached 0, 0.36 and 0.5 g/l. The apparent elimination half-life of THC was slightly prolonged (1.59 vs. 1.93 h, p < 0.05) and the concentration 1 h after smoking was slightly lower (24 vs. 17 ng/ml, p < 0.05) with the higher ethanol dose. The prolonged THC elimination might be explained by a small ethanol-mediated change in distribution to and from deep compartments. Concentrations and pharmacokinetics of 11-hydroxy-THC and 11-nor-9-carboxy-THC (THCA) were not significantly influenced by ethanol. However, THCA concentrations appeared lower in both ethanol conditions, which might also be attributable to changes in distribution. Though not significant in the present study, this might be relevant in the interpretation of cannabinoid concentrations in blood.