Phrenic and intercostal nerves with rhythmic discharge can promote early nerve regeneration after brachial plexus repair in rats

Exogenous discharge can positively promote nerve repair. We, therefore, hypothesized that endogenous discharges may have similar effects. The phrenic nerve and intercostal nerve, controlled by the respiratory center, can emit regular nerve impulses; therefore these endogenous automatically discharging nerves might promote nerve regeneration. Action potential discharge patterns were examined in the diaphragm, external intercostal and latissimus dorsi muscles of rats. The phrenic and intercostal nerves showed rhythmic clusters of discharge, which were consistent with breathing frequency. From the first to the third intercostal nerves, spontaneous discharge amplitude was gradually increased. There was no obvious rhythmic discharge in the thoracodorsal nerve. Four animal groups were performed in rats as the musculocutaneous nerve cut and repaired was bland control. The other three groups were followed by a side-to-side anastomosis with the phrenic nerve, intercostal nerve and thoracodorsal nerve. Compound muscle action potentials in the biceps muscle innervated by the musculocutaneous nerve were recorded with electrodes. The tetanic forces of ipsilateral and contralateral biceps muscles were detected by a force displacement transducer. Wet muscle weight recovery rate was measured and pathological changes were observed using hematoxylin-eosin staining. The number of nerve fibers was observed using toluidine blue staining and changes in nerve ultrastructure were observed using transmission electron microscopy. The compound muscle action potential amplitude was significantly higher at 1 month after surgery in phrenic and intercostal nerve groups compared with the thoracodorsal nerve and blank control groups. The recovery rate of tetanic tension and wet weight of the right biceps were significantly lower at 2 months after surgery in the phrenic nerve, intercostal nerve, and thoracodorsal nerve groups compared with the negative control group. The number of myelinated axons distal to the coaptation site of the musculocutaneous nerve at 1 month after surgery was significantly higher in phrenic and intercostal nerve groups than in thoracodorsal nerve and negative control groups. These results indicate that endogenous autonomic discharge from phrenic and intercostal nerves can promote nerve regeneration in early stages after brachial plexus injury.

角膜生物力学测量方法及临床应用

角膜是人眼球屈光系统的重要组成部分,角膜的生物材料性质确定了其在角膜扩张和相关疾病中发挥重要作用。本文对角膜生物力学的离体测量、在体测量方法进行了总结,并对角膜生物力学在系统性疾病、扩张性角膜病、青光眼、近视等眼科疾病中的特点与临床应用进行了回顾。

Ultrasound-triggered microbubble destruction enhances the radiosensitivity of glioblastoma by inhibiting PGRMC1-mediated autophagy in vitro and in vivo

Background:Ultrasound-triggered microbubble destruction(UTMD) is a widely used noninvasive technology in both military and civilian medicine,which could enhance radiosensitivity of various tumors.However,little information is available regarding the effects of UTMD on radiotherapy for glioblastoma or the underlying mechanism.This study aimed to delineate the effect of UTMD on the radiosensitivity of glioblastoma and the potential involvement of autophagy.Methods:GL261,U251 cells and orthotopic glioblastoma-bearing mice were treated with ionizing radiation(IR) or IR plus UTMD.Autophagy was observed by confocal microscopy and transmission electron microscopy.Western blotting and immunofluorescence analysis were used to detect progesterone receptor membrane component 1(PGRMC1),light chain 3 beta 2(LC3B2) and sequestosome 1(SQSTM1/p62) levels.Lentiviral vectors or siRNAs transfection,and fluorescent probes staining were used to explore the underlying mechanism.Results:UTMD enhanced the radiosensitivity of glioblastoma in vitro and in vivo(P<0.01).UTMD inhibited autophagic flux by disrupting autophagosome-lysosome fusion without impairing lysosomal function or autophagosome synthesis in IR-treated glioblastoma cells.Suppression of autophagy by 3-methyladenine,bafilomycin A1 or ATG5 siRNA had no significant effect on UTMD-induced radiosensitization in glioblastoma cells(P<0.05).Similar results were found when autophagy was induced by rapamycin or ATG5 overexpression(P>0.05).Furthermore,UTMD inhibited PGRMC1expression and binding with LC3B2 in IR-exposed glioblastoma cells(P<0.01).PGRMC1 inhibitor AG-205 or PGRMC1siRNA pretreatment enhanced UTMD-induced LC3B2 and p62 accumulation in IR-exposed glioblastoma cells,thereby promoting UTMD-mediated radiosensitization(P<0.05).Moreover,PGRMC1 overexpression abolished UTMD-caused blockade of autophagic degradation,subsequently inhibiting UTMD-induced radiosensitization of glioblastoma cells.Finally,compared with IR plus UTMD group,PGRMC1 overexpression significantly increased tumor size [(3.8±1.1) mm^(2)vs.(8.0±1.9) mm^(2),P<0.05] and decreased survival time [(67.2±2.6) d vs.(40.0±1.2) d,P=0.0026] in glioblastoma-bearing mice.Conclusions:UTMD enhanced the radiosensitivity of glioblastoma partially by disrupting PGRMC1-mediated autophagy.

Switch-on fluorescence sensor for ascorbic acid detection based on MoS2 quantum dots-MnO2 nanosheets system and its application in fruit samples

In this work,molybdenum disulfide quantum dots（MoS2 QDs） were firstly prepared by hydrothermal method using sodium molybdate and glutathione as precursors,and applied in ascorbic acid detection.When joining MnO2 nanosheets into MoS2 QDs solution,they produced an obvious fluorescence quenching,which should be due to inner filter effect（IFE）.Meanwhile,the fluorescent probe was formed,Interestingly,we found that this quenching phenomenon disappeared with the addition of ascorbic acid,In other words,the fluorescence gradually restored.This recovery phenomenon is mainly due to the reduction effect of ascorbic acid for MnO2 nanosheets.Under the optimum conditions,the limit of detection（LOD） of 39 nmol/L for ascorbic acid was achieved with a linear range of 0.33-5.00 μmol/L.The repeatability was better than 5.0% for ascorbic acid in both standard and fruit samples（n = 3）.Moreover,the as-fabricated fluorescent sensing system was successfully employed to detect the ascorbic acid levels in hawthorn and jujube with satisfactory results.

Practice and reflection on the teaching of the reproductive system

Objective To review and explore the advantages and disadvantages of the teaching of the reproductive system in Shanghai Jiao Tong University School of Medicine,in order to provide a feasible scheme for the subsequent reform of the teaching system,including the syllabus design and the optimization of the teaching method,etc.Methods With the one-year practice in the teaching of the reproductive system,this paper has explored the achievements in the implementation of this teaching system from three aspects,including the teaching experience and feelings of teachers,student questionnaires and test scores.Meanwhile,this paper has also deeply analyzed some problems that may exist or be derived from the teaching practice in that teaching model.Results The new teaching method has huge differences from the traditional"discipline-oriented"teaching method in the curricular design,teachers’lecture form,students’learning skills and examination types,etc.What is more important,the new teaching method will significantly renew the concepts of both teaching and learning.Conclusion The method of the systemic teaching is one of the critical ways to realize the reform of the medical education,and can also provide the necessary basis for the cultivation of professional high-quality teachers required in the medical education.