Exercise Reveals the Interrelation of Physical Fitness,Inflammatory Response,Psychopathology, and Autonomic Function in Patients With Schizophrenia

Maintaining and improving fitness are associated with a lower risk of premature death from cardiovascular disease. Patients with schizophrenia are known to exercise less and have poorer health behaviors than average. Physical fitness and physiological regulation during exercise tasks have not been investigated to date among patients with schizophrenia. We studied autonomic modulation in a stepwise exhaustion protocol in 23 patients with schizophrenia and in matched controls, using spirometry and lactate diagnostics. Parameters of physical capacity were determined at the aerobic, anaerobic, and vagal thresholds (VT), as well as for peak output. VT was correlated with psychopathology, as assessed by the Positive and Negative Syndrome Scale, with the inflammatory markers IL-1β, IL-6, and TNF-α and with peak output. The MANOVA for heart and breathing rates, as well as for vagal modulation and complexity behavior of heart rate, indicated a profound lack of vagal modulation at all intensity levels, even after the covariate carbon monoxide concentration was introduced as a measure of smoking behavior. Significantly decreased physical capacity was demonstrated at the aerobic, anaerobic, and VT in patients. After the exercise task, reduced vagal modulation in patients correlated negatively with positive symptoms and with levels of IL-6 and TNF-α. This study shows decreased physical capacity in patients with schizophrenia. Upcoming intervention studies need to take into account the autonomic imbalance, which might predispose patients to arrhythmias during exercise. Results of inflammatory parameters are suggestive of a reduced activity of the anti-inflammatory cholinergic pathway in patients, leading to a pro-inflammatory state.Key words: heart rate, physical exercise, respiration, schizophrenia, vagal threshold, cardiac death, inflammation, physical fitness     

Real‐Time Visualization of Platelet Interaction With Micro Structured Surfaces

Improving the hemocompatibility of artificial implants by micro structuring their surfaces has shown promising results, but the mechanisms which lead to this improvement are not yet understood. Therefore, we built a test setup for real‐time visualization of platelet interaction with a plain and two micro structured surfaces. The micro structures, defined by the distance of the plain surface area between the structures, were chosen to be 3 and 30 μm, representing a positive and a negative effect on the hemocompatibility. The main part of the test setup was a flow chamber containing films of low density polyethylene (LDPE) with the differently structured surfaces. For different wall shear stresses, no considerable differences were observed in the platelet‐surface interaction for all surface types. Whereas, major differences in flow behavior were observed when comparing the surfaces to each other. The platelets “rolled” along the smooth surface, being in constant contact with the surface material. Although the platelets “rolled” over the surface with small structures as well, they were only in contact with the tips of the structure and therefore had less surface contact with the foreign material. The increased distance and height of the structures of the last surface led to a trapping of platelets between the structures. This resulted in a longer contact time with the foreign material as well as a larger contact area, which both increase the risk of platelet activation, adhesion, and finally clotting. Our results showed the mechanisms which lead to these effects and thus revealed why micro structuring of surfaces impacts the hemocompatibility. Furthermore, we established a test setup which can be used for future investigations on the platelet‐structure interactions.     

Expression of transforming growth factor-beta receptor type 1 and type 2 in human sporadic vestibular Schwannoma

Expression of the transforming growth factor-beta (TGF-beta) protein family in the peripheral nervous system is well established, but the role of their cognate receptors TGF-beta receptor type 1 (R1) and type 2 (R2) has been less well studied. TGF-beta plays an essential role in Schwann cell proliferation and differentiation, and is involved in neurotrophic effects of several neurotrophic substances. TGF-beta is also expressed in benign peripheral nervous system tumors such as vestibular schwannomas. In the present study, we aimed to detect TGF-beta R1 and R2 in a total of 40 sporadic vestibular schwannomas using immunohistochemistry, and correlated the findings to essential clinicopathologic data. TGF-beta, TGF-beta R1, and TGF-beta R2 mRNA was further analyzed by RT-PCR in six vestibular schwannomas. TGF-beta R1 immunoexpression was found in about 95% of the tumors. TGF-beta R1 was equally present in Antoni A and Antoni B areas of the tumors. TGF-beta R2 was found immunohistochemically in 77%. In addition, all tumors showed strong expression of TGF-beta. No correlation between TGF-beta R1 or R2 expression and clinicopathologic parameters such as age, sex, clinical symptoms, growth pattern, and proliferation acitivity as measured by Ki-67 (MIB-1) staining was found. Moreover, all schwannomas studied contained TGF-beta, TGF-beta R1, and TGF-beta R2 mRNA. Therefore, the TGF-beta/TGF-beta R1 and -R2 system is present in human schwannomas, but its biologic role for tumor development and growth remains unclear.     

Comparison of Longitudinal and Apical Foetal Speckle Tracking Echocardiography Using Tissue Motion Annular Displacement and Segmental Longitudinal Strain

The aim of our prospective pilot study with exploratory analysis was to compare longitudinal and apical foetal speckle tracking echocardiography (STE) using tissue motion annular displacement (TMAD) and segmental longitudinal strain (SLS). We compared two different STE quantification tools in a longitudinal and apical four-chamber view in 57 normal foetuses between 20 and 40 wk of gestation. Myocardial mechanical dyssynchrony and strain were assessed using offline quantification software (QLab Version 10.3, Philips Medical Systems, Andover, MA, USA). We compared the dyssynchrony measurements with TMAD and SLS in longitudinal and apical four-chamber views. Furthermore, we examined the segmental strain values of both ventricles with SLS and compared the differences between longitudinal and apical measurements. Dyssynchrony measurements with TMAD and SLS and strain measurements with SLS were feasible in all cases. In the apical view, the dyssynchrony measurements with TMAD were systematically greater than those achieved with SLS (p < 0.001). For the longitudinal view, no differences were observed between tools (p?=?0.153). The application of SLS provided similar results for dyssynchrony in both views (intra-class correlation coefficient [ICC]?=?0.281, p?=?0.623), but the strain measurements in the left and right ventricles differed significantly between views (ICC?=?–0.082, p?=?0.011, and ICC?=?–0.061, p?=?0.024, respectively). For TMAD, we found large differences in the dyssynchrony values between longitudinal and apical assessment (ICC?=?–0.060, p?=?0.03). Furthermore, TMAD exhibited reduced accuracy in the system's automatic tracking algorithm, limiting the data quality. The dyssynchrony assessment is affected less by the foetal position in SLS than in TMAD. The strain readings in SLS varied depending on the view in which they were assessed. The application of TMAD cannot be recommended for foetal STE.     

The variability of atlas-based targets in relation to surrounding major fibre tracts in thalamic deep brain stimulation

Background

In essential tremor (ET), the main target for deep brain stimulation (DBS) is the thalamic ventralis intermedius nucleus (Vim). This target cannot be identified on conventional magnetic resonance imaging (MRI). Therefore, targeting depends on probabilistic coordinates derived from stereotactic atlases. The goal of our study was to investigate the variability of atlas-based Vim targets in relation to surrounding major fibre tracts.

Methods

With the MRI and computed tomography (CT) scan data of ten patients who underwent DBS, we planned atlas based Vim targets in both hemispheres. We also performed deterministic fibre-tracking with diffusion tensor imaging (DTI) of the dentato-rubro-thalamic tract (DRTT), pyramidal tract (PT) and lemniscus medialis (LM) in all 20 hemispheres. Subsequently, we measured the distance from the atlas-based Vim target to each tract along the medial/lateral (x-coordinate), anterior/posterior (y-coordinate) and superior/inferior axis (z-coordinate).

Results

Seventeen out of 20 DRTTs could be depicted with our standardised DTI/fibre-tracking parameters. The PT and the LM could be displayed in all 20 hemispheres. The atlas-based Vim target was found inside the DRTT in 11 (concerning the x-coordinate) and 10 hemispheres (concerning the z-coordinate). Regarding the anterior/posterior direction, the target was posterior to the DRTT in 11 cases. In 19 hemispheres the Vim target was located medial and superior to the PT and in 17 hemispheres posterior to it. Concerning the LM, the Vim target was found inside the LM in 16 (regarding the x-coordinate) and in 14 cases (regarding the z-coordinate). In eight cases it was located inside and in 12 cases anterior to the LM concerning the y-coordinate.

Conclusions

We found a considerable variability of the location of atlas-based target points of the ventralis intermedius nucleus in relation to neighbouring major fibre tracts in individual patients. These results suggest that individualised targeting to structures not directly visible on conventional MRI is necessary.