Adaptations to Postural Perturbations in Patients With Freezing of Gait

Introduction: Freezing of gait (FOG) is a powerful determinant of falls in Parkinson's disease (PD). Automatic postural reactions serve as a protective strategy to prevent falling after perturbations. However, differences in automatic postural reactions between patients with and without FOG in response to perturbation are at present unclear. Therefore, the present study aimed to compare the response patterns and neuromuscular control between PD patients with and without FOG and healthy controls (HCs) after postural perturbations.Methods: 28 PD patients (15 FOG+, 13 FOG−) and 22 HCs were included. Participants stood on a moveable platform while random perturbations were imposed. The first anterior platform translation was retained for analysis. Center of pressure (CoP) and center of mass (CoM) trajectories and trunk, knee and ankle angles were compared between the three groups using the Statistical Parametric Mapping technique, allowing to capture changes in time. In addition, muscle activation of lower leg muscles was measured using EMG.Results: At baseline, FOG+ stood with more trunk flexion than HCs (p = 0.005), a result not found in FOG−. Following a perturbation, FOG+ reacted with increased trunk extension (p = 0.004) in comparison to HCs, a pattern not observed in FOG−. The CoM showed greater backward displacement in FOG− and FOG+ (p = 0.008, p = 0.027). Both FOG+ and FOG− showed increased co-activation of agonist and antagonist muscles compared to HCs (p = 0.010), with no differences between FOG+ and FOG−.Conclusions: Automatic postural reactions after a sudden perturbation are similar between PD subgroups with and without FOG but different from HCs. Reactive postural control, largely regulated by brain stem centers, seems to be modulated by different mechanisms than those governing freezing of gait. Greater differences in initial stance position, enhanced by joint stiffening, could however underlie maladaptive postural responses and increase susceptibility for balance loss in FOG+ compared to FOG−

Prevalence and severity of antipsychotic related constipation in patients with schizophrenia: a retrospective descriptive study

<p>Abstract</p> <p>Background</p> <p>Antipsychotic are the cornerstone in the treatment of schizophrenia. They also have a number of side-effects. Constipation is thought to be common, and a potential serious side-effect, which has received little attention in recent literature.</p> <p>Method</p> <p>We performed a retrospective study in consecutively admitted patients, between 2007 and 2009 and treated with antipsychotic medication, linking different electronic patient data to evaluate the prevalence and severity of constipation in patients with schizophrenia under routine treatment conditions.</p> <p>Results</p> <p>Over a period of 22 months 36.3% of patients (99) received at least once a pharmacological treatment for constipation. On average medication for constipation was prescribed for 273 days. Severe cases (N = 50), non-responsive to initial treatment, got a plain x-ray of the abdomen. In 68.4% fecal impaction was found.</p> <p>Conclusion</p> <p>A high prevalence of constipation, often severe and needing medical interventions, was confirmed during the study period. Early detection, monitoring over treatment and early intervention of constipation could prevent serious consequences such as ileus.</p

First laser ions at the CERN-MEDICIS facility

The CERN-MEDICIS facility aims to produce emerging medical radionuclides for the theranostics approach in nuclear medicine with mass separation of ion beams. To enhance the radioisotope yield and purity of collected samples, the resonance ionization laser ion source MELISSA was constructed, and provided the first laser ions at the facility in 2019. Several operational tests were accomplished to investigate its performance in preparation for the upcoming production of terbium radioisotopes, which are of particular interest for medical applications. © 2020, The Author(s).KU LeuvenHorizon 2020: 642889 MEDICIS-PROMED05P12UMCIA, 05P15UMCIAOpen Access funding provided by Projekt DEAL. We would like to acknowledge the help and assistance from the whole MEDICIS collaboration; from CERN-ISOLDE Technical and Physical groups. This research project has been supported by a Marie Skłodowska-Curie Innovative Training Network Fellowship of the European Commission’s Horizon 2020 Programme under contract number 642889 MEDICIS-PROMED; by the German Federal Ministry of Education and Research under the consecutive projects 05P12UMCIA and 05P15UMCIA; by the Research Foundation Flanders FWO (Belgium) and by a KU Leuven START grant

Differential regulation of Knotted1-like genes during establishment of the shoot apical meristem in Norway spruce (Picea abies)

Establishment of the shoot apical meristem (SAM) in Arabidopsis embryos requires the KNOXI transcription factor SHOOT MERISTEMLESS. In Norway spruce (Picea abies), four KNOXI family members (HBK1, HBK2, HBK3 and HBK4) have been identified, but a corresponding role in SAM development has not been demonstrated. As a first step to differentiate between the functions of the four Norway spruce HBK genes, we have here analyzed their expression profiles during the process of somatic embryo development. This was made both under normal embryo development and under conditions of reduced SAM formation by treatment with the polar auxin transport inhibitor NPA. Concomitantly with the formation of an embryonic SAM, the HBK2 and HBK4 genes displayed a significant up-regulation that was delayed by NPA treatment. In contrast, HBK1 and HBK3 were up-regulated prior to SAM formation, and their temporal expression was not affected by NPA. Ectopic expression of the four HBK genes in transgenic Arabidopsis plants further supported similar functions of HBK2 and HBK4, distinct from those of HBK1 and HBK3. Together, the results suggest that HBK2 and HBK4 exert similar functions related to the SAM differentiation and somatic embryo development in Norway spruce, while HBK1 and HBK3 have more general functions during embryo development

Asymmetric leaves1 mediates leaf patterning and stem cell function in Arabidopsis

Meristem function in plants requires both the maintenance of stem cells and the specification of founder cells from which lateral organs arise. Lateral organs are patterned along proximodistal, dorsoventral and mediolateral axes (1,2). Here we show that the Arabidopsis mutant asymmetric leaves1 (as1) disrupts this process. AS1 encodes a myb domain protein, closely related to PHANTASTICA in Antirrhinum and ROUGH SHEATH2 in maize, both of which negatively regulate knotted-class homeobox genes. AS1 negatively regulates the homeobox genes KNAT1 and KNAT2 and is, in turn, negatively regulated by the meristematic homeobox gene SHOOT MERISTEMLESS. This genetic pathway defines a mechanism for differentiating between stem cells and organ founder cells within the shoot apical meristem and demonstrates that genes expressed in organ primordia interact with meristematic genes to regulate shoot morphogenesi

Laser-assisted nuclear decay spectroscopy of 176,177,179Au

A study of the laser-ionized and mass-separated neutron-deficient isotopes Au-176,Au-177,Au-179 was performed using the Resonance Ionization Laser Ion Source and the Windmill detection setup at ISOLDE, CERN. New and improved data on complex fine-structure alpha decays of the three isotopes were deduced, providing insight into the low-lying levels in the daughter nuclei Ir-172,Ir-173,Ir-175. New information on the properties of beta-decay daughter products Pt-177,Pt-179 was also obtained. From the first in-source laser spectroscopy measurements of the hyperfine structure in the atomic 267.6-nm transition of Au-176, the nuclear magnetic moments for both high- and low-spin alpha-decaying states were deduced. Together with the values determined from the additivity relations, they were used to propose the most probable spins and configurations for both states. The a-decay branching ratios were determined as b(alpha)(Au-176(1s)) = 58(5)% and b(alpha)(Au-176(hs)) = 29 (5)%

On track? A study on the effects of tracks in secondary education

Tracking is the grouping of students with similar abilities in the same classroom or school during secondary education. For each group, a tailored educational program is provided, which is called a 'track'. Many education systems use this practice, based on the assumption that fitting educational environments to more homogeneous student groups will result in more efficient education. Tracking also allows for the development of specialized skills in the different tracks. This skill specialization helps the education system to meet the needs of the labor market. However, it remains unclear whether and to what extent a track affects a student's outcomes. Therefore, in this dissertation we assessed the effects of going to school in a certain track on several outcomes. In Flanders, students must choose a track at the end of primary education, when they are 12 years of age. Tracks attract students based on their academic abilities (e.g., academic performance in mathematics and reading comprehension). Therefore, each track differs in the average academic performance of its students at the start of secondary education. Based on these differences, the tracks can be hierarchically ranked. Because each track attracts students with different abilities and socioeconomic backgrounds, differences between student outcomes across tracks are partially attributable to these initial differences. Hence, to estimate the effects of tracks, the methodological challenge was to account for differences between students prior to initial track allocation. Track choice in Flanders is generally free at the start of secondary education. However, a student who does not meet the level of his or her track will be forced to go to a 'lower' track. That many students change from a higher to a lower track over time is considered a unique characteristic of Flemish education. Students who change track also differ from students who remain in their track. Hence, a second methodological challenge was to account for differences between students who change track and students who remain in their track. We used two longitudinal datasets of secondary education, the contemporary LiSO-dataset and the older LOSO-dataset. To account for the differences between students, both matching methods and G-methods were used. Matching was done by using propensity scores, but we also used Mahalanobis distances and coarsened variables. G-methods either used propensity scores or directly used the estimation of track allocation probabilities. Note that these methods only work if comparable students exist across tracks. Therefore, the effect of a track was estimated for three pairs of tracks, with each pair consisting of hierarchically consecutive tracks. The effects of tracks were assessed for academic performance, unemployment, academic self-concept and engagement. The results showed that being allocated to a higher track always positively affects academic performance. Being allocated to the higher track also reduced the probabilities of becoming unemployed, although the differences were generally small. For academic self-concept it was usually best to be allocated to a lower track, but this was not the case for the classical and modern track comparison. In which track a student goes to school mattered little for engagement.status: publishe