17 research outputs found
In Vitro Evaluation of Guanidine Analogs as Sigma Receptor Ligands for Potential Anti-Stroke Therapeutics
Fixed lumbar apical vertebral rotation predicts spinal decompensation in lenke type 3c adolescent idiopathic scoliosis after selective posterior thoracic correction and fusion
Retrospective radiographic review of surgically treated double major curves (Lenke type 3C) in adolescent idiopathic scoliosis. To evaluate the role of selective posterior thoracic correction and fusion in double major curves with third generation instrumentation and to identify preoperative radiographic parameters that predict postoperative coronal spinal decompensation. Traditionally the surgical treatment of double major curves consists of fusion of both the thoracic and the lumbar curve. Few attempt to perform selective thoracic fusion in this curve pattern because of the potential to create spinal imbalance. Thirty-six patients with Lenke type 3C curves underwent a selective posterior thoracic correction and fusion with either CotrelâDubousset instrumentation or the Universal Spine System. Radiographs were evaluated to assess coronal and sagittal balance, curve flexibility, and curve correction at a minimum follow up of 2 years. Postoperative coronal spinal decompensation was investigated with respect to preoperative radiographic parameters on standing anteroposterior (AP), standing lateral radiographs, thoracic and lumbar supine side-bending radiographs. Coronal spinal decompensation was defined as plumbline deviation of C7 of more than 2 cm with respect to the centre sacral vertical line (CSVL) within 2 years of surgery. Twenty-six patients (72%) showed satisfactory frontal plane alignment patients (28%) showed coronal spinal decompensation. Significant group differences, however, were identified for lumbar apical vertebral rotation, measured according to Perdriolle (La scoliose. Son ĂȘtude tridimensionnelle. Maloine, Paris, pp 179, 1979) (A 16°, B 22°, P = 0.02), percentage correction (derotation) of lumbar apical vertebrae in lumbar supine side-bending films in comparison to standing AP radiographs (A 49%, B 27%, P = 0.002) and thoracic curve flexibility (A 43%, B 25%, P = 0.03). High correlation was noted between postoperative decompensation and derotation of lumbar apical vertebrae in pre-operative lumbar supine side-bending films with a critical value of 40% (Pearson correlation coefficient; P = 0.62, P < 0.001). Ten of 36 patients (28%) with Lenke type 3C adolescent idiopathic scoliosis showed coronal spinal decompensation of more than 2 cm after selective posterior thoracic correction and fusion. Lumbar apical vertebral derotation of less than 40% provided the radiographic prediction of postoperative coronal spinal imbalance. We advise close scrutiny of the transverse plane in the lumbar supine bending film when planning surgical strategy
Aseptic stem loosening in primary THA: migration analysis of cemented and cementless fixation
Early migration has reportedly been predictive for later implant failure. Using four different migration patterns, this study aimed to analyse migration behaviour of the two types of implant fixationâcemented and cementlessâthroughout the process of loosening. Migrational behaviour of 69 revised stems (49 cemented, 20 uncemented) was analysed retrospectively with EBRA-FCA (Einzel-Bild-Röntgen-Analyse, Femoral Component Analysis). Uncemented stems failed after early and late onset migration alike, while late migration was the predominant pattern in cemented stems. Mean prosthetic failure after early migration occurred 5.8 (±4.4) years postoperatively due to insufficient primary stability. Initially stable stems with late onset migration were revised after 12.4 (±4.5) years. Measurement of early migration was found to be a valuable tool to screen short-term and mid-term failure. In the long run the methodâs sensitivity decreased. Late onset migration, however, preceded long-term failure by a mean of three years
Electromyogram and kinematic analysis of lateral bending in idiopathic scoliosis patients.
In adolescent idiopathic scoliosis (AIS), surgical planning currently relies on spinal flexibility evaluation using lateral bending radiographs. The aim was to evaluate the feasibility of non-invasive dynamic analysis of trunk kinematics and muscle activity in patients with AIS before surgical correction. During various lateral trunk bending tasks, erector spinae (18 sites) and abdominal (four sites) muscle activity was sampled using surface electrodes in ten AIS patients and in ten controls. Simultaneously, the spatial displacements of infrared emitting diodes located on the trunk were sampled. Parameters considered were the heterolateral-to-homolateral root-mean-square EMG ratios R at each site and total lateral bending and thoracic and lumbar curvature angle courses. Main alterations concerned apical muscle activity during left bending tasks. ANOVA results showed a significant effect of side (p = 2.1 x 10(-9)), EMG recording site (p = 1.9 x 10(-16)), pathology (p = 3.9 x 10(-16)) and task (p = 2.2 x 10(-11)) on R ratios. The R ratio at T10 and L1 for a simple lateral bending task during left bending averaged 4.8 (SD 4.3) and 3.0 (SD 3.1) in AIS patients, and 2.3 (SD 2.8) and 1.3 (SD 0.4) in controls (p = 6.4 x 10(-4) and 2.5 x 10(-3), LSD post hoc). This preliminary study allowed the development of a functional, non-invasive, non-irradiating dynamic tool for pre-operative evaluation in AIS.Journal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe
LymphocyteâActivation Gene 3 Facilitates Pathological Tau NeuronâtoâNeuron Transmission
Abstract The spread of prionâlike protein aggregates is a common driver of pathogenesis in various neurodegenerative diseases, including Alzheimer's disease (AD) and related Tauopathies. Tau pathologies exhibit a clear progressive spreading pattern that correlates with disease severity. Clinical observation combined with complementary experimental studies has shown that Tau preformed fibrils (PFF) are prionâlike seeds that propagate pathology by entering cells and templating misfolding and aggregation of endogenous Tau. While several cell surface receptors of Tau are known, they are not specific to the fibrillar form of Tau. Moreover, the underlying cellular mechanisms of Tau PFF spreading remain poorly understood. Here, it is shown that the lymphocyteâactivation gene 3 (Lag3) is a cell surface receptor that binds to PFF but not the monomer of Tau. Deletion of Lag3 or inhibition of Lag3 in primary cortical neurons significantly reduces the internalization of Tau PFF and subsequent Tau propagation and neuronâtoâneuron transmission. Propagation of Tau pathology and behavioral deficits induced by injection of Tau PFF in the hippocampus and overlying cortex are attenuated in mice lacking Lag3 selectively in neurons. These results identify neuronal Lag3 as a receptor of pathologic Tau in the brainïŒand for AD and related Tauopathies, a therapeutic target