Prediction of spine decompression post-surgery outcome through transcranial motor evoked potential using linear discriminant analysis algorithm

Transcranial motor evoked potential (TcMEP) is one of the modalities in intraoperative neuromonitoring (IONM) which has been used in spine surgeries to prevent motor function injuries. Studies have shown that improvement to TcMEP could be a potential prognostic information on the actual improvement to the patient after surgery. There is no objective way currently to identify which TcMEP signal is significant to indicate actual positive relief of symptoms. The proposed method utilized linear discriminant analysis (LDA) machine learning algorithm to predict the TcMEP response that correlates to relieve of symptoms post-surgery. TcMEP data were obtained from four patients that had pre surgery symptoms with post-surgery actual relief of symptoms, and six patients that had no pre surgery and post-surgery symptoms which were divided into training and prediction test. The result of the proposed method produced 87.5% of accuracy in prediction capabilities

Cell growth, cell-cycle progress, and antibody production in hybridoma cells cultivated under mild hypothermic conditions

The effect of mild hypothermic (32 degrees C) conditions on cell growth, cell-cycle progress, and antibody production of hybridoma C2E7 cells was investigated in the present study. The growth of hybridoma cells was slower during the mild hypothermic condition compared to that at 37 degrees C; this led to about 10% decrease in maximum viable cell density and volumetric antibody productivity. However, under mild hypothermic growth conditions, the culture viability was substantially improved and the specific antibody productivity was enhanced compared to that at 37 degrees C. The average specific productivity for the entire batch culture at 32 degrees C is about 5% higher than that at 37 degrees C. Cell-cycle analysis data showed that there was no growth arrestment during the mild hypothermic growth of hybridoma cells. The G1-phase cells were increased, while the S-phase cells were decreased gradually as the culture time progressed. Further analysis showed that the specific antibody productivity of hybridoma cells was correlated to the fraction of S-phase cells

Biological Tissues as Active Nematic Liquid Crystals

International audienc

Emergent patterns of collective cell migration under tubular confinement

Collective epithelial behaviours are studied in vitro in the context of flat sheets but a system to mimic tubular systems is lacking. Here, the authors develop a method to study collective behaviour in lumenal structures and show that several features depend on the extent of tubular confinement and/or curvature

U-shaped sacral fracture: An easily missed fracture with high morbidity. A report of two cases.

U-shaped sacral fracture is a very rare injury. This injury is easily missed and the diagnosis is often delayed as it is difficult to detect on the anteroposterior view of the pelvic radiograph. It is highly unstable and neurological injury is common. Two cases of U-shaped sacral fractures are reported here in which the diagnosis was delayed resulting in the late development of cauda equina syndrome. In these two cases, full recoveries were achieved following surgical decompression. A high index of suspicion with proper clinical and radiographic assessments will decrease the incidence of missed diagnosis and prevent the occurrence of delayed neurological deficits

Material approaches to active tissue mechanics

International audienc

Radiological assessment of cervical lateral mass screw angulations in Asian patients

Background: Various lateral mass screw fixation methods have been described in the literature with various levels of safety in relation to the anterior neurovascular structures. This study was designed to radiologically determine the minimum lateral angulations of the screw to avoid penetration of the vertebral artery canalusing three of the most common techniques: Roy-Camille, An, and Magerl. Materials and Methods: Sixty normal cervical CT scans were reviewed. A minimum lateral angulation of a 3.5 mm lateral mass screw which was required to avoid penetration of the vertebral artery canal at each level of vertebra were measured. Results: The mean lateral angulations of the lateral mass screws (with 95% confidence interval) to avoid vertebral artery canal penetration, in relation to the starting point at the midpoint (Roy-Camille), 1 mm medial (An), and 2 mm medial (Magerl) to the midpoint of lateral mass were 6.8° (range, 6.3-7.4°), 10.3° (range, 9.8-10.8°), and 14.1° (range, 13.6-14.6°) at C3 vertebrae; 6.8° (range, 6.2-7.5°), 10.7° (range, 10.0-11.5°), and 14.1° (range, 13.4-14.8°) at C4 vertebrae; 6.6° (range, 6.0-7.2°), 10.1° (range, 9.3-10.8°), and 13.5° (range, 12.8-14.3°) at C5 vertebrae and 7.6° (range, 6.9-8.3°), 10.9° (range, 10.3-11.6°), and 14.3° (range, 13.7-15.0°) at C6 vertebrae. The recommended lateral angulations for Roy-Camille, Magerl, and An are 10°, 25°,and 30°, respectively. Statistically, there is a higher risk of vertebral foramen violation with the Roy-Camille technique at C3, C4 and C6 levels, P < 0.05. Conclusions: Magerl and An techniques have a wide margin of safety. Caution should be practised with Roy-Camille′s technique at C3, C4, and C6 levels to avoid vertebral vessels injury in Asian population

Introduction – Our place in time: A preliminary reflection

Our Place in Time: Exploring Heritage and Memory in Singapore1-1

Topological defects in epithelia govern cell death and extrusion

International audienc

Epithelial Cell Packing Induces Distinct Modes of Cell Extrusions.

International audienceThe control of tissue growth, which is a key to maintain the protective barrier function of the epithelium, depends on the balance between cell division and cell extrusion rates [1, 2]. Cells within confluent epithelial layers undergo cell extrusion, which relies on cell-cell interactions [3] and actomyosin contractility [4, 5]. Although it has been reported that cell extrusion is also dependent on cell density [6, 7], the contribution of tissue mechanics, which is tightly regulated by cell density [8-12], to cell extrusion is still poorly understood. By measuring the multicellular dynamics and traction forces, we show that changes in epithelial packing density lead to the emergence of distinct modes of cell extrusion. In confluent epithelia with low cell density, cell extrusion is mainly driven by the lamellipodia-based crawling mechanism in the neighbor non-dying cells in connection with large-scale collective movements. As cell density increases, cell motion is shown to slow down, and the role of a supracellular actomyosin cable formation and its contraction in the neighboring cells becomes the preponderant mechanism to locally promote cell extrusion. We propose that these two distinct mechanisms complement each other to ensure proper cell extrusion depending on the cellular environment. Our study provides a quantitative and robust framework to explain how cell density can influence tissue mechanics and in turn regulate cell extrusion mechanisms