Relationships between neighborhood walkability and adults' physical activity: How important is residential self-selection?

The study's aims were to examine whether residential self-selection differed according to socio-demographic characteristics and objectively assessed neighborhood walkability; and, whether objectively assessed walkability was a significant correlate of physical activity (PA) beyond residential self-selection. In total, 412 adults (aged 20-65 years) completed a socio-demographic questionnaire, the long IPAQ, a neighborhood selection questionnaire and wore an accelerometer for seven days. Walkability characteristics were an important reason for selecting the current neighborhood and were more important for women, older and less-educated adults, but not for high-walkable neighborhood residents. Both in the total sample and in participants with high residential self-selection scores, walkability was positively related to active transportation and objectively measured moderate-to-vigorous PA. Designing walkable neighborhoods may help to increase adults' PA, even in those for whom walkability is an important criterion when choosing their neighborhood. However, findings from studies with longitudinal and controlled designs are required to provide more strongly causal evidence.     

Insurance choice and tax-preferred health savings accounts

We develop an infinite horizon utility maximization model of the interaction between insurance choice and tax-preferred health savings accounts. The model can be used to examine a wide range of policy options, including flexible spending accounts, health savings accounts, and health reimbursement accounts. We also develop a 2-period model to simulate various implications of the model. Key results from the simulation analysis include the following: (1) with no adverse selection, use of unrestricted health savings accounts leads to modest welfare gains, after accounting for the tax revenue loss; (2) with adverse selection and an initial pooling equilibrium comprised of "sick" and "healthy" consumers, introducing HSAs can, but does not necessarily, lead to a new pooling equilibrium. The new equilibrium results in a higher coinsurance rate, an increase in expected utility for healthy consumers, and a decrease in expected utility for sick consumers; (3) with adverse selection and a separating equilibrium, both sick and healthy consumers are better off with a health savings account; (4) efficiency gains are possible when insurance contracts are explicitly linked to tax-preferred health savings accounts.     

L’émotion. Approche clinique et informatique

Emotion occurs in a number of mental disturbances, but being the object of multiple definitions it still remains poorly specified. In order to obtain a better definition of emotion, the authors have confronted their respective models in an interdisciplinary perspective and have shown that their models do combine. The clinician has taken as the object of his study traumatic phobia and has isolated a certain number of components, and links by successive abstractions. The systems analyst has relied on a construction based on software to compute an organization, which could represent a metaphorical emotive-affective system. The points where these respective models meet are underlined. They connect with biomental automatisms at three successive stages: with primary reflexes, with desynchronization of constituted cycles, and with emotional experience, permitting to isolate and validate a structure of emotion. Emotion, thus, appears to be the product of a disturbance of automated processes which link three instances (unconsciousness, preconsciousness and consciousness), a disturbance which can have effects on the functioning of the various components of the system as well as on the functioning of the whole system.     

A comparison of the outgrowth potentials of split-thickness skin grafts sectioned by scalpel, mechanical mesher, and CO2 laser.

Mechanical meshers that press blades through immobilized skin are routinely used to expand split-thickness skin grafts, and scanned incisional lasers are currently under investigation for the same purpose. However, in contrast to the atraumatic wound edge that is created on these grafts by a sliding scalpel blade, the skin "crushing" and skin coagulation that can occur with the use of mechanical meshers and lasers are thought to reduce the outgrowth potential of the epidermis. With the use of an in vitro explant outgrowth system, epithelialization derived from wound edges that were created by a scalpel, a mechanical mesher, and a CO2 laser at various settings was studied. The area of epithelialization around skin explants was not significantly different for skin bridges produced by scalpel cuts and those produced by the skin mesher, and histologic sections demonstrated similar epiboly-growth under these explants. In contrast, wounds created with the CO2 laser showed impaired epithelialization. Incisions were made at several power settings, ranging from 11 passes at 4 mW to 1 pass at 24 mW. Only minor differences were demonstrated, with the lower laser power yielding slightly better results. Recruitment of keratinocytes into the proliferative state, as assessed by bromodeoxyuridine incorporation, was equivalent for scalpel and mesh cut skin. This data does not support concerns about decreased graft viability resulting from the crushing blade action used by mechanical meshers. The possibility of cutting and meshing skin grafts with lasers of the far-infrared and mid-infrared light spectrum are discussed.     

Backpacks and spinal disorders in school children

The interest on backpacks, particularly with regard to their potential unfavourable effect on spinal disorders in school children, has dramatically increased during the last years. The aim of the present study was to look critically at the recent publications and to qualify some 'common sense-based rules'. In recent studies no or weak associations between spinal disorders in children and backpack use could be identified, which is related to the methodology of the studies. From reviewing the biomechanical and physiological effects of backpack use, it was concluded that there is evidence that carrying a heavy backpack results in trunk forward lean and that there are indications that backpack use can increase metabolic cost and alter gait kinetics in youngsters. However there is no evidence that postural, metabolic or kinetic adaptations to backpack use, cause back disorders at young age. Spinal forces based on the above mentioned postural responses can be presumed. However, the amount of work represented by the school backpacks should be compared with the physical activities performed by the same youngsters during their leisure time and is probably not as dangerous as claimed in some media. Therefore the uproar in medical and educational societies and in the media, to sensitize children, parents and educators, with weight cut-off limitations and other backpack use safety guidelines can not be justified and overmedicalizing this issue should be avoided.     

Fibrin,the preferred scaffold for cell transplantation after myocardial infarction? An old molecule with a new life

Fibrin is a topical haemostat, sealant and tissue glue, which consists of concentrated fibrinogen and thrombin. It has broad medical and research uses. Recently, several studies have shown that engineered patches comprising mixtures of biological or synthetic materials and progenitor cells showed therapeutic promise for regenerating damaged tissues. In that context, fibrin maintains cell adherence at the site of injury, where cells are required for tissue repair, and offers a nurturing environment that protects implanted cells without interfering with their expected benefit. Here we review the past, present and future uses of fibrin, with a focus on its use as a scaffold material for cardiac repair. Fibrin patches filled with regenerative cells can be placed over the scarring myocardium; this methodology avoids many of the drawbacks of conventional cell‐infusion systems. Advantages of using fibrin also include extraction from the patient's blood, an easy readjustment and implantation procedure, increase in viability and early proliferation of delivered cells, and benefits even with the patch alone. In line with this, we discuss the numerous preclinical studies that have used fibrin–cell patches, the practical issues inherent in their generation, and the necessary process of scaling‐up from animal models to patients. In the light of the data presented, fibrin stands out as a valuable biomaterial for delivering cells to damaged tissue and for promoting beneficial effects. However, before the fibrin scaffold can be translated from bench to bedside, many issues must be explored further, including suboptimal survival and limited migration of the implanted cells to underlying ischaemic myocardium. Copyright © 2016 John Wiley & Sons, Ltd.     

The effects of concurrent administration of +/-3,4-methylenedioxymethamphetamine and cocaine on conditioned place preference in the adult male rat

Conditioned place preference (CPP), a commonly used model for studying the role of contextual cues in drug reward and drug seeking, was employed to explore possible behavioral interactions between (+/-)3,4-methylenedioxymethamphetamine (MDMA; "ecstasy") and cocaine. On each of four occasions, adult male rats received one of three doses of MDMA (0 mg/kg, 5 mg/kg, 10 mg/kg; administered subcutaneously [s.c.]) combined with one of three doses of cocaine (0 mg/kg, 2.5 mg/kg, 5 mg/kg; administered intraperitoneally [i.p.]), and were then tested in a CPP paradigm. The results showed MDMA-induced CPP at a unit dose of 5 mg/kg, but at the 10 mg/kg dose there was a return to baseline (control) performance levels. For cocaine alone, CPP increased in a linear fashion as the drug dose was increased. Concurrent administration resulted in antagonism of each drug, but there was evidence that this pattern was reversible at higher doses of the respective drugs. These data are instructive insofar as they suggest that the behavioral and neurochemical effects of MDMA and cocaine presented in isolation are dramatically altered when the two drugs are presented in combination.     

Localization of needle tip with color doppler during pericardiocentesis: In vitro validation and initial clinical application.

This study evaluates a new device that uses color Doppler ultrasonography to enable real-time image guidance of the aspirating needle, which has not been possible until now. The ColorMark device (EchoCath Inc, Princeton, NJ) induces high-frequency, low-amplitude vibrations in the needle to enable localization with color Doppler. We studied this technique in 25 consecutive patients undergoing pericardiocentesis, and in vitro, in a urethane phantom with which the accuracy of color Doppler localization of the needle tip was compared with that obtained by direct measurement. Tip localization was excellent in vitro; errors axial to the ultrasound beam (velocity Doppler -0.13 +/- 0.90 mm, power Doppler -0.05 +/- 1.7 mm) were less than lateral errors (velocity -0.36 +/- 1.8 mm, power -0.02 +/- 2.8 mm). In 18 of 25 patients, the needle was identified and guided into the pericardial space with the ColorMark technique, and it allowed successful, uncomplicated drainage of fluid. Initial failures were the result of incorrect settings on the echocardiographic machine and inappropriate combinations of the needle puncture site and imaging window. This study demonstrates a novel color Doppler technique that is highly accurate at localizing a needle tip. The technique is feasible for guiding pericardiocentesis. Further clinical validation of this technique is required.