Osteoarthritis (OA) is the most common joint disease worldwide. Recent studies have shown that targeted disruption of Smad3 in mouse results in OA. To reveal the possible association between the Smad3 gene mutation and human OA, we employed polymerase chain reaction-single strand conformation polymorphism and sequencing to screen mutations in all nine exons of the Smad3 gene in 32 patients with knee OA and 50 patients with only bone fracture. A missense mutation of the Smad3 gene was found in one patient. The single base mutation located in the linker region of the SMAD3 protein was A-T change in the position 2 of codon 197 and resulted in an asparagine to isoleucine amino-acid substitution. The expressions of matrix metalloproteinase 2 (MMP-2) and MMP-9 in sera of the patient carrying the mutation were higher than other OA patients and controls. This is the first report showing that the Smad3 gene mutations could be associated with the pathogenesis of human OA.

This paper introduces an interactive Unity3D-based three-dimensional virtual practice platform for chemical-engineering, which is intended to assist the chemical engineering students in their production practice. The real chemical plant sections are recreated in the virtual environment of the system. The system provides users with two kinds of walkthrough modes, demonstration of the structure and operation principle of some main equipment as well as the operating functions of setting up some major pumps and valves so as to strengthen the students' understanding of the chemical process and train their operative ability. In addition, its virtual treatment of emergency can help to enhance the safety production awareness of the students and cultivate their ability to respond to unexpected emergency. The students' feedback to our survey indicates that, despite some suggestions for further improvement, the virtual platform has more advantages and characteristics compared with traditional practice mode, and is effective in helping them understand the chemical process and equipment. What is more, some improvement has been made to perfect the system with students' suggestions fully taken into consideration.

Objectives: To investigate the potential protective effect of ischemic post-conditioning (Post-con) on ischemia-reperfusion injury of the rabbit spinal cord, and to determine if there is an additive neuroprotective effect when ischemic preconditioning (IPC) and Post-con are combined.Methods: Forty New Zealand white rabbits were randomly divided into four groups: group Control (C; n = 10), aortic occlusion (AOC; for 30 min; group IPC (n = 10) three cycles of three-minute AOC plus three-minute reperfusion before the 30-min AOC; group Post-con (n = 10), three cycles of threeminute reperfusion plus three-minute AOC immediately upon reperfusion after 30-min AOC; group IPC+Post-con (n = 10), where animals were subjected to both IPC and Post-con. At six hours, 24 hr and 48 hr following reperfusion, neurological function was assessed according to Tarlov scores, and at 48 hr, the spinal cords were procured for the histopathologic evaluation, by comparing the number of intact α-motor neurons in the anterior horn. Results:The median count (and quartiles) of intact α-motor neurons was greatest in group Post-con 73 (69-76) and group IPC+Post-con 29 (22-42) compared to the numbers of viable α-motor neurons in groups C 6 (4-9) and IPC 15 (11-18) (P < 0.001). The numbers of animals who developed paraplegia according to Tarlov criteria were 7/10 in groups Post-con and IPC+Post-con, compared to 9/10 animals in each of groups C and IPC. Conclusions:This laboratory investigation provides histological evidence that Post-con may protect the spinal cord from moderate to severe ischemia reperfusion injury. Ischemic preconditioning conferred no additional benefits in this rabbit model. The results have potential clinical implications for patients undergoing thoracoabdominal aortic reconstructive surgery. et le groupe , que le nombre de neurones moteurs-α viables dans les (P < 0,001 et déterminer s'il y a un effet neuro-protecteur lors de la combinaison du pré-conditionnement ischémique (PCI) et du Post-con. Méthode : Quarante lapins blancs de Nouvelle-Zélande ont été répartis en quatre groupes de façon aléatoire : groupe témoin (T ; n = 10), occlusion aortique (OCA) de 30 min ; groupe PCI (n = 10), trois cycles de reperfusion de trois minutes plus OCA de trois minutes immédiatement à la reperfusion après une OCA de 30 min ; groupe PCI+Post-con (n = 10), dans lequel les animaux ont été soumis à un PCI et un Post-con. Six heures, 24 h et 48 h après reperfusion, la fonction neurologique a été évaluée selon le barème de Tarlov, et à 48 h, les moelles épinières étaient soumises à une évaluation histo-pathologique, en comparant le nombre de neurones moteurs-α intacts au niveau de la corne antérieure. Résultats : Le nombre médian (et les quartiles) de neurones moteurs-α intacts fut plus élevé dans le groupe

Our recent study demonstrated that acetylcholinesterase (AChE) activity at the neuromuscular junction (NMJ) of the diaphragm decreased during sepsis. However, the mechanisms were not clearly identified. In this study, we aimed to investigate whether the decreased AChE activity was related to oxidative stress by observing AChE activity in different grades of sepsis induced by caecal ligation and puncture (CLP). At 24 h after surgery, an assay of thiobarbituric acid reactive species (TBARS) and protein carbonyls, as well as the myeloperoxidase (MPO), superoxide dismutase (SOD), and catalase (CAT) activity, was conducted. AChE activity was measured by biochemical and histological detection. AChE and CAT activity in the diaphragm decreased, while the contents of TBARS and protein carbonyls, the activity of MPO and SOD, and the SOD/CAT ratios increased. The above changes were much more significant in the mid-grade septic group than in the low-grade septic group. The colour of the AChE activity staining at the NMJ gradually lightened from the sham surgery group to the mid-grade septic group. AChE activity was significantly negatively correlated with the levels of TBARS and protein carbonyls. We consider that oxidative stress might be responsible for decreased AChE activity in the diaphragms of rats induced with sepsis.