Repair, protection and regeneration of peripheral nerve injury

Reading guide 1778Repair of long-segment peripheral nerve defects1779Bionic reconstruction of hand function after adult brachial plexus root avulsion1780Optimized design of regeneration material for the treatment of peripheral nerve injury1781Synergism of electroactive polymeric materials and electrical stimulation promotes peripheral nerve repair1783Schwann cell effect on peripheral nerve repair and regeneration .

Protection of 3'-methoxy-puerarin against focal brain ischemia and its association with c-fos expression

The present study established a rat model of focal brain ischemia by occlusion of the middle cerebral artery covered with FeCl3, and investigated the protective effect of 3＇-methoxy-puerarin. Hippocampal and cortical c-fos gene expression was determined using in situ hybridization. Results showed that 3＇-methoxy-puerarin reduced neurological deficit scores, cerebral infarcted zone and water content of brain tissues, dramatically increased the activity of catalase and glutathione peroxidase in the ischemia zone of the hippocampus, increased the activity of catalase in the cortex, decreased lipid peroxide and lactic acid contents in the hippocampus and cerebral cortex, and down-regulated c-fos gene expression in brain ischemic rats. Results demonstrated that 3＇-methoxy-puerarin exhibited cerebroprotective effects against focal brain ischemia, which involved c-fos gene expression.

The key target of neuroprotection after the onset of ischemic stroke: secretory pathway Ca^(2+)-ATPase 1

The regulatory mechanisms of cytoplasmic Ca2＋ after myocardial infarction-induced Ca2＋ overload involve secretory pathway Ca2＋-ATPase 1 and the Golgi apparatus and are well understood. However, the effect of Golgi apparatus on Ca2＋ overload after cerebral ischemia and reperfusion remains unclear. Four-vessel occlusion rats were used as animal models of cerebral ischemia. The expression of secretory pathway Ca2＋-ATPase 1 in the cortex and hippocampus was detected by immunoblotting, and Ca2＋ concentrations in the cytoplasm and Golgi vesicles were determined. Results showed an overload of cytoplasmic Ca2＋ during ischemia and reperfusion that reached a peak after reperfusion. Levels of Golgi Ca2＋ showed an opposite effect. The expression of Golgi-specific secretory pathway Ca2＋-ATPase 1 in the cortex and hippocampus decreased before ischemia and reperfusion, and increased after reperfusion for 6 hours. This variation was similar to the alteration of calcium in separated Golgi vesicles. These results indicate that the Golgi apparatus participates in the formation and alleviation of calcium overload, and that secretory pathway Ca2＋-ATPase 1 tightly responds to ischemia and reperfusion in nerve cells. Thus, we concluded that secretory pathway Ca2＋-ATPase 1 plays an essential role in cytosolic calcium regulation and its expression can be used as a marker of Golgi stress, responding to cerebral ischemia and reperfusion. The secretory pathway Ca2＋-ATPase 1 can be an important neuroprotective target of ischemic stroke.

Hyperbaric oxygen preconditioning improves postoperative cognitive dysfunction by reducing oxidant stress and inflammation

Postoperative cognitive dysfunction is a crucial public health issue that has been increasingly studied in efforts to reduce symptoms or prevent its occurrence. However, effective advances remain lacking. Hyperbaric oxygen preconditioning has proved to protect vital organs, such as the heart, liver, and brain. Recently, it has been introduced and widely studied in the prevention of postoperative cognitive dysfunction, with promising results. However, the neuroprotective mechanisms underlying this phenomenon remain controversial. This review summarizes and highlights the definition and application of hyperbaric oxygen preconditioning, the perniciousness and pathogenetic mechanism underlying postoperative cognitive dysfunction, and the effects that hyperbaric oxygen preconditioning has on postoperative cognitive dysfunction. Finally, we conclude that hyperbaric oxygen preconditioning is an effective and feasible method to prevent, alleviate, and improve postoperative cognitive dysfunction, and that its mechanism of action is very complex, involving the stimulation of endogenous antioxidant and anti-inflammation defense systems.

The astrocyte scar – not so inhibitory after all?

Damaged adult central nervous system axons have very limited regenerative capacity,if any.Other than an intrinsic deficiency（Liu et al.,2011）in axonal extension and guidance compared to embryonic neurons or peripheral neurons,the injury site is also generally viewed to be non-permissive for axonal regrowth.In particular,

The complex contribution of the astrocyte scar

It is tempting to assign positive or negative roles to components of neurotrauma pathology,in an effort to generate an ordered picture and design therapeutic strategies accordingly.However nature is seldom so obliging.This principle is elegantly illustrated in a recent publication from Anderson,

历史文化街区更新实施中的社区信任建构--以北京史家胡同为例

Concerning the complexity and diversity of demands in historic and cultural districts,the protection and regeneration planning(PRP)practice has been gradually shifted from spatial design to pluralistic and participatory community governance.Previous studies have pointed out that community trust is an essential means to eliminate social resistance and improve community cohesion and executive capability.However,the trustbuilding mechanism has been given little attention in urban planning.This study intends to improve the theoretical cognition of trust in community governance and provide suggestions for addressing issues of protection and regeneration planning in historic and cultural districts.With Shijia Hutong in Dongcheng District of Beijing,as an empirical case,this paper conducts a household survey and applies the Structural Equation Model(SEM)to explore the influencing elements and community trust-building path in the protection and regeneration planning from the perspective of residents.Through analyzing the influencing mechanism of residents’perception,it reveals that,firstly,pluralistic governance that is composed of the grass-roots government,NGOs,and residents can directly promote residents’perception of the protection and regeneration planning,and have a greater influence by facilitating public participation in building up community trust.Secondly,residents’perception of the protection and regeneration planning would not be improved if public participation failed to build up community trust.Thirdly,community trust consists of neighborhood trust and leadership trust,of which the latter is more important.These findings contribute a new perspective and solution to urban regeneration and heritage protection in the future.In addition,this study may inspire research on trust-building through urban planning,governance,and public participation.