Diffusion model for iontophoresis measured by laser-Doppler perfusion flowmetry, applied to normal and preeclamptic pregnancies

We present a physical model to describe iontophoresis time recordings. The model is a combination of monodimensional material diffusion and decay, probably due to transport by blood flow. It has four adjustable parameters, the diffusion coefficient, the decay constant, the height of the response, and the shot saturation constant, a parameter representing the relative importance of subsequent shots (in case of saturation). We test the model with measurements of blood perfusion in the capillary bed of the fingers of women who recently had preeclampsia and in women with a history of normal pregnancy. From the fits to the measurements, we conclude that the model provides a useful physical description of the iontophoresis process. (c) 2007 Society of Photo-Optical Instrumentation Engineers.</p

Psychosis as an Evolutionary Adaptive Mechanism to Changing Environments

Background: From an evolutionary perspective it is remarkable that psychotic disorders, mostly occurring during fertile age and decreasing fecundity, maintain in the human population. Aim: To argue the hypothesis that psychotic symptoms may not be viewed as an illness but as an adaptation phenomenon, which can become out of control due to different underlying brain vulnerabilities and external stressors, leading to social exclusion. Methods: A literature study and analysis. Results: Until now, biomedical research has not unravelld the definitive etiology of psychotic disorders. Findings are inconsistent and show non-specific brain anomalies and genetic variation with small effect sizes. However, compelling evidence was found for a relation between psychosis and stressful environmental factors, particularly those influencing social interaction. Psychotic symptoms may be explained as a natural defense mechanism or protective response to stressful environments. This is in line with the fact that psychotic symptoms most often develop during adolescence. In this phase of life, leaving the familiar, and safe home environment and building new social networks is one of the main tasks. This could cause symptoms of “hyperconsciousness” and calls on the capacity for social adaptation. Conclusions: Psychotic symptoms may be considered as an evolutionary maintained phenomenon.Research investigating psychotic disorders may benefit from a focus on underlying general brain vulnerabilities or prevention of social exclusion, instead of psychotic symptoms

Psychosis as an evolutionary adaptive mechanism to changing environments

__Background:__ From an evolutionary perspective it is remarkable that psychotic disorders, mostly occurring during fertile age and decreasing fecundity, maintain in the human population. __Aim:__ To argue the hypothesis that psychotic symptoms may not be viewed as an illness but as an adaptation phenomenon, which can become out of control due to different underlying brain vulnerabilities and external stressors, leading to social exclusion. __Methods:__ A literature study and analysis. __Results:__ Until now, biomedical research has not unravelld the definitive etiology of psychotic disorders. Findings are inconsistent and show non-specific brain anomalies and genetic variation with small effect sizes. However, compelling evidence was found for a relation between psychosis and stressful environmental factors, particularly those influencing social interaction. Psychotic symptoms may be explained as a natural defense mechanism or protective response to stressful environments. This is in line with the fact that psychotic symptoms most often develop during adolescence. In this phase of life, leaving the familiar, and safe home environment and building new social networks is one of the main tasks. This could cause symptoms of "hyperconsciousness" and calls on the capacity for social adaptation. __Conclusions:__ Psychotic symptoms may be considered as an evolutionary maintained phenomenon. Research investigating psychotic disorders may benefit from a focus on underlying general brain vulnerabilities or prevention of social exclusion, instead of psychotic symptoms

Telemedicine in interdisciplinary work practices: On an IT system that met the criteria for success set out by its sponsors, yet failed to become part of every-day clinical routines

Background. Information systems can play a key role in care innovations including task redesign and shared care. Many demonstration projects have presented evidence of clinical and cost effectiveness and high levels of patient satisfaction. Yet these same projects often fail to become part of everyday clinical routines. The aim of the paper is to gain insight into a common paradox that a technology can meet the criteria for success set out at the start of the project yet fail to become part of everyday clinical routines. Methods. We evaluated a telecare service set up to reduce the workload of ophthalmologists. In this project, optometrists in 10 optical shops made digital images to detect patients with glaucoma which were furth