The Achyranthes bidentata polypeptide k fraction enhances neuronal growth in vitro and promotes peripheral nerve regeneration after crush injury in vivo

We have previously shown that Achyranthes bidentata polypeptides （ABPP）, isolated from Achyranthes bidentata Blume （a medicinal herb）, exhibit neurotrophic and neuroprotective effects on the nervous system. To identify the major active component of ABPP, and thus optimize the use of ABPP, we used reverse-phase high performance liquid chromatography to separate ABPP. We obtained 12 fractions, among which the fraction of ABPPk demonstrated the strongest neuroactivity. Immunocytochemistry and western blot analysis showed that ABPPk promoted neurite growth in cultured dorsal root ganglion explant and dorsal root ganglion neurons, which might be associated with activation of Erk1/2. A combination of behavioral tests, electrophysiological assessment, and histomorphometric analysis indicated that ABPPk enhanced nerve regeneration and function restoration in a mouse model of crushed sciatic nerve. All the results suggest that ABPPk, as the key component of ABPP, can be used for peripheral nerve repair to yield better outcomes than ABPP.

Matrix metalloproteinase 9 level as an indicator for restenosis following cervical and intracranial angioplasty and stenting

Cervical and intracranial angioplasty and stenting is an effective and safe method of reducing the risk of ischemic stroke, but it may be affected by in-stent restenosis. The present study in-vestigated serum level of matrix metalloproteinase 9 as a predictor of restenosis after 40 patients underwent cervical and/or intracranial angioplasty and stenting. Results showed that resteno-sis occurred in 30% （3/10） of patients when the serum level of matrix metalloproteinase 9 at 3 days after surgery was 2.5 times higher than preoperative level. No restenosis occurred when the serum level of matrix metalloproteinase 9 at 3 days after surgery was not 2.5 times higher than preoperative level. Restenosis occurred in 12% （2/17） of patients when the serum level of matrix metalloproteinase 9 was higher than preoperative level for more than 30 days after surgery, but only occurred in 4% （1/23） of patients when the serum level of matrix metalloproteinase 9 was higher than preoperative level for less than 30 days after surgery. However, the differences observed were not statistically signiifcant （P 〉 0.05）. Experimental ifndings indicate that when the serum level of matrix metalloproteinase 9 is 2.5 times higher than preoperative level at 3 days after cervi-cal and intracranial angioplasty and stenting, it may serve as a predictor of in-stent restenosis.

Immunity phenomena following olfactory ensheathing cell transplantation into experimental allergic encephalomyelitis rat brain

Olfactory ensheathing cells （OECs） can promote axonal regeneration and remyelination for the treatment of spinal cord injury. OECs can also treat experimental allergic encephalomyelitis （EAE）, but it remains unclear whether OECs might be rejected by the immune system in the brain including the destruction of the blood-brain barrier under inflammation, the release of inflammatory factors, the activation of local antigen-presenting cells （e.g., microglia cells） and antigen drainage. We found that OECs expressed major histocompatibility complex （MHC）-I molecules on the cell surface, barely expressed MHC-II, but MHC-II could be induced by interferon-v, suggesting that OECs have certain immunogenicity. When OECs were transplanted into normal animal brains, no OECs were phagocytosed by dendritic cells in the cervical lymph node, and OECs did not induce lymphocyte proliferation, which indicates that OECs share some immune privilege under normal conditions. However, OECs in the rat EAE brain were phagocytosed by dendritic cells in the cervical lymph node and enhanced lymphocyte proliferation. These findings suggest that OECs are rejected because of increased immunogenicity in EAE brain, and that brain inflammation, in particular activated dendritic cells, may be a prerequisite for rejecting OECs.

Lysosomal Exocytosis in Schwann Cells Contributes to Axon Remyelination

髓鞘形成是一个包括协同性的胞吐、内吞、mRNA转运和细胞骨架的动态变化的复杂过程。尽管髓鞘的异常在溶酶体贮积症中很常见,但对溶酶体在髓鞘形成和维持中所扮演的角色仍不清楚。本文发现Schwann细胞中的晚期内涵体/溶酶体包含大量的髓鞘蛋白P0,含量占超过一半的外周神经系统中的致密髓鞘的总蛋白并且在不同的刺激下表现出Ca2+依赖性的胞吐作用。Rab27a(一种将分泌溶酶体运输至细胞膜的小GTP酶)下调,极大地阻碍了Schwann细胞中的溶酶体胞吐作用,减少了再生坐骨神经的髓鞘形成。这些发现强调了Schwann细胞中溶酶体的新角色,提示调节Schwann细胞中的溶酶体胞吐作用在外周神经系统中有很重要的生理和病理意义。

Critical signaling pathways during Wallerian degeneration of peripheral nerve

Wallerian degeneration is a critical biological process that occurs in distal nerve stumps after nerve injury. To systematically investigate molecular changes underlying Wallerian degeneration, we used a rat sciatic nerve transection model to examine microarray analysis outcomes and investigate significantly involved Kyoto Enrichment of Genes and Genomes（KEGG） pathways in injured distal nerve stumps at 0, 0.5, 1, 6, 12, and 24 hours, 4 days, 1, 2, 3, and 4 weeks after peripheral nerve injury. Bioinformatic analysis showed that only one KEGG pathway（cytokine-cytokine receptor interaction） was significantly enriched at an early time point（1 hour post-sciatic nerve transection）. At later time points, the number of enriched KEGG pathways initially increased and then decreased. Three KEGG pathways were studied in further detail： cytokine-cytokine receptor interaction, neuroactive ligand-receptor interaction, and axon guidance. Moreover, temporal expression patterns of representative differentially expressed genes in these KEGG pathways were validated by real time-polymerase chain reaction. Taken together, the above three signaling pathways are important after sciatic nerve injury, and may increase our understanding of the molecular mechanisms underlying Wallerian degeneration.

Sensitive Voltammetric Determination of Mitoxantrone by Using CS-Dispersed Graphene Modified Glassy Carbon Electrodes

A novel CS-dispersed graphene modified glassy carbon electrode was fabricated. Study electrochemical characteristics of mitoxantrone in the CS-dispersed graphene modified electrode by cyclic voltammetry and other methods, by selecting and optimizing the various parameters to create a new electrochemical method for the determination of mitoxantrone. The linear range of the oxidation peak current is from 6×10–10 to 1 ×10–6 mol/l in this method, after 2.5 mins open-circuit accumulation, the limit of detection is 2×10–10 mol/l. After 10 parallel determinations, the relative standard deviation was 3.7% that the concentration of mitoxantrone was 1×10–8 mol/l. The modified electrode has been successfully applied for the assay of mitoxantrone in human urine samples.

Preparation of Functional Magnetic Nanoparticles and its Application in Diagnostic Analysis

The magnetic nanoparticles modified with carboxyl functional group were synthesized and characterized. These nanoparticles covalently bound with hepatitis B surface antibody（HBsAb）, were used to detect hepatitis B surface antigen （HBsAg） in immunovoltammetry. The detection limit was found to be 0.06 ng/mL, which is much higher than that of enzyme-linked immunosorbent assay （ELISA） used in clinical analysis.

Safety of endovascular therapy for symptomatic intracranial artery stenosis:a national prospective registry

Introduction The safety outcomes of endovascular therapy for intracranial artery stenosis in a real-world stetting are largely unknown.The Clinical Registration Trial of Intracranial Stenting for Patients with Symptomatic Intracranial Artery Stenosis(CRTICAS)was a prospective,multicentre,real-world registry designed to assess these outcomes and the impact of centre experience.Methods 1140 severe,symptomatic intracranial arterial stenosis(ICAS)patients treated with endovascular therapy were included from 26 centres,further divided into three groups according to the annual centre volume of intracranial angioplasty and stent placement procedures over 2 years:(1)high volume for≥25 cases/year;(2)moderate volume for 10–25 cases/year and(3)low volume for<10 cases/year.Results The rate of 30-day stroke,transient ischaemic attack or death was 9.7%(111),with 5.4%,21.1%and 9.7%in high-volume,moderate-volume and low-volume centres,respectively(p<0.05).Multivariable logistic regression confirmed high-volume centres had a significantly lower primary endpoint compared with moderate-volume centres(OR=0.187,95%CI:0.056 to 0.627;p≤0.0001),while moderate-volume and low-volume centres showed no significant difference(p=0.8456).Conclusion Compared with the preceding randomised controlled trials,this real-world,prospective,multicentre registry shows a lower complication rate of endovascular treatment for symptomatic ICAS.Non-uniform utilisation in endovascular technology,institutional experience and patient selection in different volumes of centres may have an impact on overall safety of this treatment.

Low-temperature synthesis of sea urchin-like Co-Ni oxide on graphene oxide for supercapacitor electrodes

Transition metal oxides are ideal electrode materials used for supercapacitors.However,the synthesis of transition metal oxides suffers from drawbacks such as high reaction temperature and energy consumption.Herein,we report the synthesis of sea urchin-like Co3 O4-NiO composites supported on graphene oxide(GO) using a hydrothermal method followed by calcination with a low temperature(250℃).The obtained Co3O4-NiO/GO composite demonstrates a high specific capacitance of 883 F g^-1 at 1 A g^-1.Furthermore,upon coupling with an activated carbon(AC) positive electrode,an asymmetric cell of Co3 O4-NiO/GO//AC exhibits outstanding stability reflected by the high capacitance retention of 82% at a high current density of 10 A g^-1.The excellent electrochemical properties of the composite may be attributed to the good synergistic effect of Co3O4 and NiO,as well as the assembly of Co3 O4 and NiO into a sea urchin structure,which results in increased electron conductivity and more exposed electroactive sites leading to the promotion of the Faradaic redox process.

Millisecond-timescale electrodeposition of platinum atom-doped molybdenum oxide as an efficient electrocatalyst for hydrogen evolution reaction

We present a straightforward method for one-pot electrodeposition of platinum atoms-doped molybdenum oxide(Pt·MoO_(3-x))films and show their superior electrocatalytic activity in the hydrogen evolution reaction(HER).A~15-nm-thick Pt·MoO_(3-x) film was prepared by one-pot electrodeposition at-0.8 V for 1 ms.Due to considerably different solute concentrations,the content of Pt atoms in the electrode-posited composite electrocatalyst is low.No Pt crystals or islands were observed on the flat Pt-MoO_(3-x) films,indicating that Pt atoms were homogeneously dispersed within the MoO_(3-x) thin film.The catalytic performance and physicochemical features of Pt·MoO_(3-x) as a HER electrocatalyst were characterized.The results showed that our Pt·MoO_(3-x) film exhibits 23-and 11-times higher current density than Pt and MoO_(3-x) electrodeposited individually under the same conditions,respectively.It was found that the dramatic enhancement in the HER performance was principally due to the abundant oxygen defects.The use of the developed one-pot electrodeposition and doping method can potentially be extended to various catalytically active metal oxides or hydroxides for enhanced performance in various energy storage and conversion applications.