Joint replacement increases radiation exposure to the staff in angiography: A phantom study.

INTRODUCTION: The present study investigates the influence of joint prostheses on the amount of scattered radiation in a simulated angiography set-up. MATERIALS AND METHODS: A clinical angiography system (Artis Zee, Siemens Healthineers, Germany) with a water phantom as a scattering object was used. The scattered radiation of the water phantom was repeatedly measured without prosthesis, with a knee prosthesis and a hip prosthesis made from titanium, aluminum, vanadium, ceramics and polyethylene. For radiation measurement an ionization chamber (ambient dose equivalent rate from 0.1 µSv/h - 100 Sv/h, UMo, Berthold Technologies, Germany) was used. It was positioned on the right side of the phantom simulating an interventional procedure via the right femoral artery. The ionization chamber was positioned at 5 different heights (30, 100, 130, 150 and 165 cm), simulating different body parts of the interventionist. In addition, the amount of scattered radiation in relation to the tube angulation was investigated. RESULTS: Averaged over all angulations at a height of 165 cm, the radiation dose was 2.7 times higher (1935 µSv/h, p < 0.01) when a hip prosthesis was present in comparison to no prosthesis (713 µSv/h). The radiation dose was 3.9 times higher with the integration of a knee prosthesis (2778 µSv/h, p < 0.01) compared to that without prosthesis. The average radiation dose over all angulations and all heights was 1491 µSv/h without prosthesis, 4538 µSv/h with a hip prothesis and 5023 µSv/h with a knee prosthesis respectively. CONCLUSION: This experimental study shows a significant increase in the radiation dose when a joint prosthesis is present in the examination field. Special attention and sufficient radiation protection is therefore necessary for investigations with implanted prostheses.

Spatial hand representation in anorexia nervosa: a controlled pilot study.

Body representation distortion (BRD) is a core criterion of Anorexia Nervosa (AN), and is usually assessed subjectively, focusing on body shape. We aimed to develop a new assessment to evaluate body representation independently from socially-mediated body image, on a body part with low emotional salience (hands). In a monocentric open label pilot study, we measured hand representations based on explicit (verbal) and implicit (tactile) instructions. Participants, with eyes closed, had to point targeted locations (knuckles and nails of each finger) based on verbal instructions and tactile stimulations to evaluate body representations respectively. Ratios between hand width and finger length were compared between AN (n = 31) and controls (n = 31) and correlated with current body mass index, AN subtype and disease duration. To control that hand distortion was specific to body representation, we also assessed object representation. Hand representation's width/length ratio was significantly increased in patients with AN, whereas no difference was found in object representation. We found no correlation between hand wideness and clinical traits related to eating disorders. Our results propose that BRD is not limited to body parts with high emotional salience, strengthening the hypothesis that anorexia nervosa is associated with profound unspecific BRD.

[GABAergic approach of postpartum depression: A translational review of literature]. / Approche GABAergique de la dépression du post-partum : une revue critique translationnelle.

INTRODUCTION: Prevalence of postpartum depression (PPD) ranges from 10 to 15 % of parturients. The impact of the PPD is major on the maternal bond and the health of both mother and child. Its physiopathological mechanisms appear to differ from other types of depression. Today, pharmacotherapy is based on nonspecific treatment, and recent therapeutic advances in this field require a comprehensive approach of the implication of the GABAergic system in the development of PPD. Neurosteroid levels during pregnancy and after parturition and the GABA-A-r modulation are thought to be involved in PPD. OBJECTIVE: To evaluate if the GABAergic approach is relevant in postpartum depression management. METHODS: We conducted a systematic review of literature based on the MEDLINE database with the following Medical Subject Headings (MeSH): "postpartum depression", "GABA", "ganaxolone", "brexanolone", "allopregnanolone", prior to September 2019. We selected articles in English: preclinical and clinical studies, literature review, observational and therapeutic studies. RESULTS: Preclinical models (mouse and rat) show changes in GABAergic inhibition in the peripartum period and correlation between allopregnanolone and GABA-A-r plasticity. This plasticity in the peripartum period maintains levels of inhibition adapted despite increased neurosteroid levels. KO models for the GABA-A-r δ subunit develop depression and anxiety symptoms in the postpartum period, and a change in the expression of the gene coding for the GABA-R alpha-4 subunit was found. Artificial inhibition of progesterone metabolism during post-partum increased depression symptoms. GABAergic fluctuation seems to be interrelated with other systems such as those of oxytocins. A synthetic neurosteroid (SGE-516) was tested on mouse models of PPD, KO for δ-GABA-A-r or KCC2, and showed decreased depressive symptoms and better mothering. Clinical studies confirm neurosteroid fluctuation and changes in the GABAergic system during the peripartum period. Allopregnanolone is the neurosteroid the most studied in PPD, and it is elevated in the brain during the pregnancy. Studies disagree on the presence of significant differences in allopregnanolone plasma levels during pregnancy or postpartum between women with PPD or not. Women with a history of PPD have greater susceptibility to neurosteroid withdrawal. Imagery and genetical data also show a link between allopregnanolone and PPD. The GABA-A-r may not recover in time following a reduced number during pregnancy, and this mismatch between neurosteroid levels and their receptor may trigger PPD. Several randomized controlled trials investigated brexanolone administrated IV, a synthetic formulation of allopregnanolone, and demonstrated a rapid and well tolerated reduction in depressive symptoms. In March 2019 brexanolone obtained FDA approval in PPD indication under the name Zulresso. However, there are differences in the time of beginning of PPD, which could constitute different subgroups of this disease, and which physiopathology could respond to different mechanisms. Prenatal depression does not respond to a GABAergic approach, but women without any risk factor or previous mood disorder developing PPD in the weeks following childbirth could be particularly responsive to this kind of treatment. CONCLUSION: Disability to modulate GABA-A-r expression during pregnancy and restore its previous state after parturition appears to trigger PPD. The GABAergic system is a promising pharmacotherapy target. From preclinical to clinical studies for about twenty years the GABAergic system has been incriminated and targeted in this challenging mental disease.