Is an ellipsoid surface suitable to model the scapulothoracic sliding plane?

Closed loop kinematic chain approaches are commonly used to assess scapular kinematics but with heterogeneous ellipsoid calibration procedures. This study aimed to assess whether an ellipsoid surface can model the scapulothoracic sliding plane and determine the optimal number of static poses to calibrate the ellipsoid parameters. An intracortical pin with a rigid cluster of four reflective markers was inserted into the left scapular spine of two healthy males (P1 and P2). They performed arm elevations, internal rotations, ball throwing, hockey shooting, and eating movements. Ellipsoid radii and center location were functionally calibrated for each participant and each movement, either based on all frames of a movement or based on a reduced number of frames (from 3 to 200 equally position-distributed frames). Across both participants and all movements, ellipsoid radii varied up to 10.2 cm, 3.9 cm, and 18.4 cm in the antero-posterior, medio-lateral, and cranio-caudal directions, respectively. When all frames of a movement were considered for calibration, the median scapula-to-ellipsoid distance was, on average, 0.52 mm and 0.38 mm for P1 and P2, respectively. When only five frames were considered for ellipsoid calibration, the scapula-to-ellipsoid median distance slightly increased with 0.57 mm and 0.47 mm for P1 and P2, respectively. To conclude, this study highlights that an ellipsoid surface may effectively be appropriate to model the scapulothoracic sliding plane, especially when the calibration is functional, participant- and movement-specific. Furthermore, the number of poses required for the ellipsoid calibration can be reduced to five, minimizing the experimental cost.

Influence of marker weights optimization on scapular kinematics estimated with a multibody kinematic optimization

Scapular kinematic estimates are altered by soft tissue artefacts, therefore experimental and numerical methods should be developed to improve their accuracy. This study aimed to assess the influence of weights applied to the scapula markers within a closed-loop multibody kinematic optimization on scapular kinematic estimates. Fifteen healthy volunteers performed static postures mimicking analytical, daily living and sport movements. Scapulo-thoracic angles were computed either from a scapula locator as the reference, or from a closed-loop multibody-kinematic optimization (MKO) including a participant-specific point-on-ellipsoid scapulothoracic joint. Weights applied to scapula markers in the MKO were optimized to minimize the difference in scapular orientation from the reference. Optimizing weighting sets significantly (p < 0.0001) improved scapular orientation from 0.9° to 12.1° in comparison to scapular kinematics estimated with non-optimized weighting sets. The mean optimized weighting set contained no neglectable weight for all markers from the acromion to the medial border of the scapular spine but showed no significant difference (p = 0.547) compared to homogeneous weights. Optimized weighting sets were participant- and movement- specific. To conclude, homogenous weights applied on redundant markers located from acromion to scapular medial border spine are recommended when estimating scapular kinematics in upper limb MKO.

Compassion-focused therapy (CFT) for the reduction of the self-stigma of mental disorders: the COMpassion for Psychiatric disorders, Autism and Self-Stigma (COMPASS) study protocol for a randomized controlled study

BACKGROUND

People with mental disorders face frequent stigmatizing attitudes and behaviors from others. Importantly, they can internalize such negative attitudes and thus self-stigmatize. Self-stigma is involved in diminished coping skills leading to social avoidance and difficulties in adhering to care. Reducing self-stigma and its emotional corollary, shame, is thus crucial to attenuate the negative outcomes associated with mental illness. Compassion-focused therapy (CFT) is a third-wave cognitive behavioral therapy that targets shame reduction and hostile self-to-self relationship and allows for symptom improvement while increasing self-compassion. Although shame is a prominent part of the concept of self-stigma, the efficacy of CFT has never been evaluated in individuals with high levels of self-stigma. The purpose of this study is to evaluate the efficacy and acceptability of a group-based CFT program on self-stigma, compared to a psychoeducation program for self-stigma (Ending Self-Stigma) and to treatment as usual (TAU). We hypothesize that diminished shame and emotional dysregulation and increased self-compassion will mediate the relationship between self-stigma improvements post-therapy in the experimental group.

METHODS

This seven-center trial will involve 336 participants diagnosed with a severe mental illness and/or autism spectrum disorder and reporting high levels of self-stigma. Participants will be randomized into one of three treatment arms: 12 week-treatment of compassion-focused therapy (experimental arm), 12 week-treatment of Psychoeducation (active control arm), and TAU (treatment as usual-passive control arm). The primary outcome is the decrease of self-stigma scores on a self-report scale, i.e., ISMI, at 12 weeks. Secondary endpoints include sustainability of self-stigma scores (ISMI) and self-reported scores regarding target psychological dimensions, e.g., shame and emotional regulation, social functioning, and psychiatric symptoms. Assessments are scheduled at pretreatment, post-treatment (at 12 weeks), and at 6-month follow-up. Acceptability will be evaluated via (i) the Credibility and Expectancy Questionnaire at T0, (ii) the Consumer Satisfaction Questionnaire for Psychotherapeutic Services posttreatment and at 6-month follow-up, (iii) attendance, and (iv) dropout rates.

DISCUSSION

This study will evaluate the potential efficacy and acceptability of a group-based CFT program on the decrease of self-stigma and thereby contribute to the continuing development of evidence-based therapeutic interventions for the internalized stigma of mental and neurodevelopmental disorders.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05698589. Registered on January 26, 2023.

MAPSSIC, a communicating MAPS-based intracerebral positrons probe for deep brain imaging in awake and freely-moving rats

Radioisotope imaging is a powerful tool to understand the biological mechanisms in-vivo, especially in the brain of small animals, providing a significant model to study the human brain.

In this context, we have developed and built a pixelated intracerebral positron probe to be embedded on awake and freely moving small animals, typically rats. This pixelated probe will represent a key instrument for neuroscientists to study neural mechanisms and correlate them to behavioral experiments.

We describe in this paper the simulations carried out to design the intracerebral sensor, its architecture, and the detection of positrons in a volume with a couple of sensors assembled back-to-back. We also depict the architecture of the wireless acquisition system. Finally, we present the first measurements performed in real-time by this miniaturized probe with sealed radioactive sources and a 18F solution.

P3510Cardiac function and Ca2+-cycling are different according to the level of cardiac-specific FKBP12.6 overexpression

Cardiac ryanodine receptors (RyR2) have a key role in excitation-contraction coupling by releasing Ca2+ from sarcoplasmic reticulum (SR). In cardiomyocytes, two FK506 binding protein (FKBP) isoforms have been shown to bind and to stabilize RyR2 opening: FKBP12 and FKBP12.6, the later having a stronger affinity for RyR2 despite its lower abundance. Cardiac-specific FKBP12.6 overexpressing mice have fewer arrhythmias induced by β-adrenergic stimulation than wild type (WT) mice, suggesting an implication of FKBP12.6 in an antiarrhythmic mechanism. Heart failure (HF) syndrome has a high incidence of arrhythmias, which may be explained by a decrease of FKBP isoform expression.

The precise mechanism of the antiarrhythmic effect of FKBP12.6 overexpression remains unknown.

To gain insight into this mechanism, we developed 2 transgenic mouse lines with cardiac-specific moderate- (TG1) and high- (TG2) FKBP12.6 overexpression levels. We characterized cardiac function, [Ca2+]i cycling and its response to β-adrenergic stimulation in both mouse lines.

TG1 and TG2 mice developed mild and marked cardiac hypertrophy, respectively, associated with basal cardiac function increase in TG1 mice only. In stimulated cardiomyocytes, [Ca2+]i transient amplitude, measured by confocal microscopy, was higher in TG1 than in WT mice, without a significant difference in their SR Ca2+ content. The effect of β-adrenergic stimulation (50 nM isoproterenol) was attenuated in TG1 mice compared to WT mice, in association with the prevention of pro-arrhythmogenic Ca2+ release events, such as Ca2+ waves. In contrast, TG2 mice showed [Ca2+]i handling characteristics similar to HF, with slower [Ca2+]i transient relaxation. Interestingly, and contrary to HF, pro-arrhythmogenic Ca2+ release events were also reduced in TG2.

These results indicate that the level of FKBP12.6 overexpression has distinct effects on cardiac function and on Ca2+-cycling and its response to β-adrenergic stimulation.

Diagnostic value of fusion of metabolic and structural images for stereotactic biopsy of brain tumors without enhancement after contrast medium injection

BACKGROUND

The heterogeneous nature of glioma makes it difficult to select a target for stereotactic biopsy that will be representative of grade severity on non-contrast-enhanced lesion imaging. The objective of this study was to evaluate the benefit of fusion of metabolic images (PET 18F-DOPA) with magnetic resonance imaging (MRI) morphological images for cerebral biopsy under stereotactic conditions of glioma without contrast enhancement.

PATIENTS AND METHODS

This single-center prospective observational study conducted between January 2016 and April 2018 included 20 consecutive patients (mean age: 45±19.5 years; range, 9-80 years) who underwent cerebral biopsy for a tumor without MRI enhancement but with hypermetabolism on ¹⁸F-FDOPA PET (positron emission tomography). Standard ¹⁸F-FDOPA uptake value (SUV_max) was determined for diagnosis of high-grade glioma, with comparison to histomolecular results.

RESULTS

Histological diagnosis was made in all patients (100%). Samples from hypermetabolism areas revealed high-grade glial tumor in 16 patients (80%). For a SUV_max threshold of 1.75, sensitivity was 81.2%, specificity 50%, PPV 86.7% and VPN 40% for diagnosis of high-grade glioma. No significant association between SUV_max and histomolecular mutation was found.

CONCLUSION

¹⁸F-FDOPA metabolic imaging is an aid in choosing the target to be biopsied under stereotactic conditions in tumors without MR enhancement. Nevertheless, despite good sensitivity, ¹⁸F-FDOPA PET is insufficient for definitive diagnosis of high-grade tumor.

An autonomous low-power management system for energy harvesting from a miniaturized spherical piezoelectric transducer

A new spherical vibrational energy harvesting device with an additional low power management circuit for optimizing the power transfer from the mechanical vibrations to a storage capacitor is presented. The device is devoted to underwater wireless sensor network applications due to its broadband vibrational energy harvesting, sensing, and communicating facilities. The sensing node container consists of two acrylic glass (PMMA) half-spherical shells and a Pz26 piezoelectric ring clamped between the shells. The energy harvesting, the management circuit, and communication electronics were fitted within the hollow portion of the sphere. A simulation model of the energy extraction and management system using spice has been developed. This simulation shows the feasibility and efficiency of the low power extraction circuit; a level of the necessary stored voltage was set at 3 V. The numerical model was validated by underwater experimental measurements; a voltage of 3 V was obtained at the terminals of a storage capacitor (47 µF) which was sufficient to supply the communication electronics. Power harvesting performances were measured relative to the transmitter/sensor distance and the incident acoustical field excitation voltage. Finally, 175 µW of harvested power has been measured with an excitation voltage of 8 Vpp at 5 cm distance from the emitter.

Combined use of two supervised learning algorithms to model sea turtle behaviours from tri-axial acceleration data

Accelerometers are becoming ever more important sensors in animal-attached technology, providing data that allow determination of body posture and movement and thereby helping to elucidate behaviour in animals that are difficult to observe. We sought to validate the identification of sea turtle behaviours from accelerometer signals by deploying tags on the carapace of a juvenile loggerhead (Caretta caretta), an adult hawksbill (Eretmochelys imbricata) and an adult green turtle (Chelonia mydas) at Aquarium La Rochelle, France. We recorded tri-axial acceleration at 50 Hz for each species for a full day while two fixed cameras recorded their behaviours. We identified behaviours from the acceleration data using two different supervised learning algorithms, Random Forest and Classification And Regression Tree (CART), treating the data from the adult animals as separate from the juvenile data. We achieved a global accuracy of 81.30% for the adult hawksbill and green turtle CART model and 71.63% for the juvenile loggerhead, identifying 10 and 12 different behaviours, respectively. Equivalent figures were 86.96% for the adult hawksbill and green turtle Random Forest model and 79.49% for the juvenile loggerhead, for the same behaviours. The use of Random Forest combined with CART algorithms allowed us to understand the decision rules implicated in behaviour discrimination, and thus remove or group together some 'confused' or under--represented behaviours in order to get the most accurate models. This study is the first to validate accelerometer data to identify turtle behaviours and the approach can now be tested on other captive sea turtle species.

[Satisfaction survey on the use of autologous oocyte vitrification in Assisted Reproductive Technologies]

OBJECTIVES

We organized a survey for in-vitro fertilization couples who beneficiated on self-preservation of part of the oocyte cohort. The main objective was to measure couples' satisfaction. Secondary objectives were; to identify how patients had been informed; to verify that the use of the ART technique met their expectations, and how they felt about oocyte or embryo freezing.

METHODS

The data were collected by a questionnaire sent electronically to couples who had undergone partial vitrification of the oocyte cohort and at least one warming cycle. The questionnaire consisted of 2 components; one for the women and another one for their husband.

RESULTS

Eighty-eight women and 62 men responded to the survey respectively, representing 50.86% and 35.84% of the targeted patients. They were satisfied with a 90% rate, men and women combined. The information we give in the center is heard by couples and is part of the trust in the medical staff. Men are more worried than women about the risks of stimulation or ovarian pick-up and are not displeased to be called upon for sperm recovery for every attempt at oocyte warming. The ambiguity of the answers on the representation of the embryo confirms what is already described, but is independent of the acceptance of freezing whether it is oocyte or embryo.

CONCLUSION

In the same way as evaluating the results, the evaluation of patient satisfaction is useful for the implementation of therapeutic strategies and care pathways.

Effects of developmental lead exposure on the hippocampal methylome: Influences of sex and timing and level of exposure

Developmental lead (Pb) exposure results in persistent cognitive/behavioral impairments as well as an elevated risk for developing a variety of diseases in later life. Environmental exposures during development can result in a variety of epigenetic changes, including alterations in DNA methylation, that can influence gene expression patterns and affect the function and development of the nervous system. The present promoter-based methylation microarray profiling study explored the extent to which developmental Pb exposure may modify the methylome of a brain region, hippocampus, known to be sensitive to the effects of Pb exposure. Male and female Long Evans rats were exposed to 0 ppm, 150 ppm, 375 ppm, or 750 ppm Pb through perinatal exposures (gestation through lactation), early postnatal exposures (birth through weaning), or long-term postnatal exposures (birth through postnatal day 55). Results showed a significant contribution of sex to the hippocampal methylome and effects of Pb exposure level, with non-linear dose response effects on methylation. Surprisingly, the developmental period of exposure contributed only a small amount of variance to the overall data and gene ontology (GO) analysis revealed the largest number of overrepresented GO terms in the groups with the lowest level of exposure. The highest number of significant differentially methylated regions was found in females exposed to Pb at the lowest exposure level. Our data reinforce the significant effect that low level Pb exposure may have on gene-specific DNA methylation patterns in brain and that this occurs in a sex-dependent manner.

Norepinephrine infusion improves haemodynamics in the preterm infants during septic shock

AIM

This study evaluated the clinical and haemodynamic effects of norepinephrine infusion in preterm infants.

METHODS

The effects of norepinephrine therapy for refractory hypotension were evaluated in preterm infants between April 2009 and April 2011 at the neonatal intensive care unit of Sainte-Justine Hospital, Montreal, Quebec. Changes in haemodynamics and clinical parameters were analysed eight hours before and eight hours after the start of norepinephrine infusion, and eight hours after its cessation.

RESULTS

During the study, 30 preterm infants at a mean gestational age of 26.5 ± 2.6 weeks (median: 25.7, 23.4-34) and birthweight of 903 ± 437 g (median 827, 450-2550) received norepinephrine infusion for neonatal septic shock. After eight hours of treatment, mean blood pressure, urine output and FiO₂ significantly improved. Eight hours after cessation of norepinephrine infusion, the number of patients treated with other inotropes decreased significantly, 24 patients (80%) had normal mean blood pressure and 27 patients (90%) had normal urine output.

CONCLUSION

Norepinephrine therapy could be considered to improve blood pressure and urine output during neonatal septic shock in preterm infants. Further studies are needed to prove the efficacy and safety of norepinephrine infusion in neonates.

[Risk of radionecrosis after hypofractionated stereotactic radiotherapy targeting the postoperative resection cavity of brain metastases]

PURPOSE

To investigate the factors that potentially lead to brain radionecrosis after hypofractionated stereotactic radiotherapy targeting the postoperative resection cavity of brain metastases.

METHODS AND MATERIALS

A retrospective analysis conducted in two French centres, was performed in patients treated with trifractionated stereotactic radiotherapy (3×7.7Gy prescribed to the 70% isodose line) for resected brain metastases. Patients with previous whole-brain irradiation were excluded of the analysis. Radionecrosis was diagnosed according to a combination of criteria including clinical, serial imaging or, in some cases, histology. Univariate and multivariate analyses were performed to determine the predictive factors of radionecrosis including clinical and dosimetric variables such as volume of brain receiving a specific dose (V_8Gy-V_22Gy).

RESULTS

One hundred eighty-one patients, with a total of 189 cavities were treated between March 2008 and February 2015. Thirty-five patients (18.5%) developed radionecrosis after a median follow-up of 15 months (range: 3-38 months) after hypofractionated stereotactic radiotherapy. One third of patients with radionecrosis were symptomatic. Multivariate analysis showed that infra-tentorial location was predictive of radionecrosis (hazard ratio [HR]: 2.97; 95% confidence interval [95% CI]: 1.47-6.01; P=0.0025). None V_8Gy-V_22Gy was associated with appearance of radionecrosis, even if V_14Gy trended toward significance (P=0.059).

CONCLUSION

Analysis of patients and treatment variables revealed that infratentorial location of brain metastases was predictive for radionecrosis after hypofractionated stereotactic radiotherapy for postoperative resection cavities.

[Secondary megaureter: A rare complication of Deflux® endoscopic management of vesicoureteral reflux in children]

Endoscopic management is the gold standard for symptomatic low-grade vesicoureteral reflux (VUR) in children. Deflux^® (hyaluronic acid/dextranomer) injection is highly effective and has very few complications. We report on two cases of secondary megaureter after Deflux^® injections. In the first case, a boy presented with Grade 4 VUR. He received a bilateral Deflux^® injection with a total of three syringes. The postoperative ultrasound was normal. However, a check-up ultrasound 3 years later showed a significant ureteropyelocalyceal dilatation, with stasis and decreased renal function on scintigraphy, the reason why antireflux surgery (Cohen procedure) was performed. In the second case, a girl diagnosed with bilateral VUR at birth received bilateral injections with one syringe on each side at the age of 12 months. One month later, the ultrasound showed a dilation of the distal ureters (diameter of the right ureter, up to 10mm; left ureter, up to 6.7mm). The child underwent surgery 8 months later (Cohen procedure) because of iterative pyelonephritis and persistent ureter dilatation. Only one previous case has been described in the literature. In our experience, this complication has occurred only twice in 452 injections (4‰). In conclusion, endoscopic treatment with hyaluronic acid/dextranomer injection is a minimally invasive procedure that improves the situation in cases of VUR. It has few complications. Other than failure, there is a low risk of secondary expansion requiring, in our opinion, ultrasound verification over the long term.