Fluoroscopy-guided retrieval of tracheal tubular metallic stents: analysis of 45 cases / 介入放射学杂志

Objective To discuss the indications,feasibility and safety of fluoroscopy-guided retrieval of tracheal tubular metallic stents.Methods Between January 2010 to December 2014,fluoroscopy-guided retrieval of tracheal tubular metallic stent was performed in 45 patients.The stents included 36 covered stents and 9 naked stents.The mean retention time of the covered and naked stents was (3.2±0.7) months and (2.5± 1.2) months respectively.Before the retrieval of the 36 covered stents,granulation tissue hyperplasia in different degrees was observed at both ends of 15 stents,and stent fracture was found in 3 stents.Granulation tissue hyperplasia was seen in all 9 naked stents.Among the 9 naked stents,5 stents were completely embedded in the tracheal submucosal area,and 2 stents were fractured.Results Of the 45 stents,41 stents were successfully retrieved (success rate of 91.1％),including 34 covered stents (94.4％,34/36) and 7 naked stents (77.8％,7/9).Of the 41 patients whose stents were successfully retrieved,massive hemoptysis occurred in 4 patients with a mean bleeding amount of 100 ml,tracheal mucosa tear was detected in 5 patients,emergency airway stent implantation because of tracheal collapse after stent retrieval was needed in one patient,and emergency surgical suture of the trachea due to tracheal rupture was carried out in one patient.No procedure-related death occurred.Conclusion The indications of fluoroscopy-guided retrieval of tracheal tubular metallic stents include stent fracture,local excessive proliferation of granulation tissue or tumor tissue that causes tracheal restenosis,temporary tracheal stent placement for benign tracheal stenosis,intolerance to stent implantation,etc.The technique of fluoroscopy-guided retrieval of tracheal tubular metallic stent is relatively safe and less invasive;this technique can solve the complications induced by long-term retention of the stents.

Biomechanics and mechanobiology of ligaments and tendons / 医用生物力学

The International Symposium on Ligaments and Tendons (ISL&T) was inaugurated in 2000 in Orlando, Florida, USA. The primary purpose of the ISL&T was to call attention to the importance of ligament and tendon (L&T) research and to bring together bioengineers, biologists, and clinician-scientists in a forum where the most current research findings could be shared, critiqued and discussed. In each symposium since 2000, there have been a number of stimulating, thought-provoking discussions on current hot topics and future challenges. The ISL&T has taken place for 15 years now, and as a result, the L&T field has significantly expanded in quantity while the quality of research has also been greatly improved. In commemoration of the 30th anniversary of the Journal of Medical Biomechanics, this article will highlight some of the major advances in L&T research over the past three decades. Topics to be covered include tissue mechanics, mechanobiology, injury and healing mechanisms, and tissue repair and regeneration.

Functional coupling reactions of human amylin receptor and nicotinic acetylcholine receptors in rat brain neurons / 生理学报

Human amylin (hAmylin) is co-released with insulin from pancreatic B-cells and the actions of this peptide on its target tissues maintain the cell excitability and glucose homeostasis. Inappropriate control of hAmylin secretion may result in human disease, particularly Alzheimer's disease (AD). It's unknown that which kind of receptor is activated by human amylin, leading to the neurotoxicity in neurons of brain. Nicotinic acetylcholine receptors (nAChRs) are known to play a critical role in a variety of nervous diseases. In the present study, we sought to determine the inter-relationships between these two receptors by examining the actions of hAmylin and nicotine on whole-cell currents and membrane potential in basal forebrain neurons. Whole cell patch-clamp recordings were performed on enzymatically dissociated neurons of the diagonal band of Broca (DBB), a cholinergic basal forebrain nucleus. The results showed that either hAmylin or nicotine individually caused a dose-dependent (1 nmol/L-20 µmol/L) membrane depolarization and an increase in firing frequency of DBB neurons. Application of AC253, an amylin receptor antagonist, blocked the excitatory effects of not only hAmylin but also nicotine; dihydro-β-erythroidine (DHβE), a nAChR antagonist, also blocked the effects of nicotine and hAmylin. These electrophysiological results suggest that hAmylin receptor and nAChRs on DBB neurons are coupled and may function in a co-operative manner to influence the excitability of DBB neurons. This finding is important for us to understand the cause and mechanisms of AD.

The use of the matrix method for the study of human motion: theory and applications / 生物医学工程学杂志

Kinematics has been successfully used to describe body motion without reference to the kinetics (or forces causing the motion). In this article, both the theory and applications of the matrix method are provided to describe complex human motion. After the definition of a Cartesian coordinate frame is introduced, the description of transformations between multiple coordinate frames is given; the decomposition of a transformation matrix into anatomical joint motion parameters (e.g. Euler angles) is then explained. The advantages of the matrix method are illustrated by three examples related to biomechanical studies. The first describes a reaching and grasping task in which matrix transformations are applied to position the hand with respect to an object during grasping. The second example demonstrates the utility of the matrix method in revealing the coupling motion of the wrist between flexion-extension and radial-ulnar deviation. The last example highlights the indispensable use of the matrix method for the study of knee biomechanics, including the description of knee joint kinematics during functional activities and determination of in-situ ligament forces using robotic technology, which has advanced our understanding of the functions of the cruciate ligaments to knee joint kinematics. It is hoped that the theoretical development and biomechanical application examples will help the readers apply the matrix method to research problems related to human motion.