Experimental Advance in Seed Cells and Biological Scaffolds for Spinal Cord Tissue Engineering (review) / 中国康复理论与实践

Objective:To explore the problems of seed cells and biological scaffolds in spinal cord tissue engineering, and review the recent experimental research. Methods:Related literatures were searched in CNKI, Wangfang data, PubMed and Web of Science from establishment to March, 2021, and the problems and progress of seed cells, biological scaffolds and their combination were reviewed. Results:The problems of seed cells are carcinogenicity, immune rejection, ethics, low survival rate and differentiation rate after transplantation, and current researches focus on exploring new cell types, gene transfection, cell co-transplantation and pretreatment before transplantation. The problems of biological scaffold are that a single material selection cannot meet different needs, and the traditional technology cannot simulate the internal structure of spinal cord well. There were more researches focusing on new composite materials and new technology. The core problem of their combination is that the effects of different cell and scaffold combinations are different, and the current researches are mostly devoted to the continuous exploration of suitable composite mode, and try to introduce biological agents and other factors. Conclusion:Spinal cord tissue engineering has the potential to completely change the therapeutic pathway of spinal cord injury. Current experimental researches mainly base on solving the problems of seed cells and biological scaffolds of spinal cord tissue engineering, and further explore the appropriate composite mode of seed cells and biological scaffolds, so as to provide more basic evidence for its clinical application.

Co-culture of Neural Stem Cells and Spinal Cord Acellular Scaffold in Vitro / 中国康复理论与实践

Objective:To observe the adhesion, growth and differentiation of rat neural stem cells (NSCs) on spinal cord acellular scaffold (SCAS) to evaluate its feasibility for spinal cord tissue engineering. Methods:NSCs derived from neonatal Sprague-Dawley rat cerebral cortex were cultured and identified. SCAS were prepared from female Sprague-Dawley rat spinal cord tissues using modified chemical extraction and physical oscillation, and evaluated. The third generation NSCs were planted on SCAS and co-cultured, the morphology of the cells on the scaffold was observed with immunofluorescence, immunohistochemistry and scanning electron microscope. Results:The cultured cells were NSCs, which could proliferate and differentiate. The porosity, water content and enzymatic hydrolysis rates of the prepared SCAS were significantly higher than that of normal spinal cord (|t| > 4.679, P < 0.01). The matrix structure of SCAS was loosely network-like, with few residual nuclei. NSCs adhered and grew well, and differentiated into neurons and glial cells on SCAS. Conclusion:This kind of SCAS shapes multi-channel spatial structure and is suitable for NSCs adhesion, growth and differentiation, which can be used for spinal cord tissue engineering.

Effect of Task-based Rehabilitation Training on Neural Circuit Plasticity and Forelimb Motor Function post Spinal Cord Injury in Mice / 中国康复理论与实践

Objective:To explore the effect of task-based rehabilitative training on neural circuit plasticity and forelimb motor function after C5 spinal cord injury in mice. Methods:A total of 21 healthy C57/BL mice were randomly and equally divided into sham group, model group and training group. The model was established by left C5 spinal cord crush injury. The lamina was removed without damaging the spinal cord in the sham group. Four weeks after injury, the training group received task-based rehabilitative training for four weeks. The horizontal ladder and rearing tests were used to assess motor function for forelimb before injury, and three days, two weeks, four weeks, six weeks and eight weeks after injury. The axons of the corticospinal tract in all mice were observed six weeks after injury by using biotinylated dextran amin (BDA) anterograde tracing. Eight weeks after injury, motor-evoked potential was applied to measure nerve conduction velocities in forelimb, while the axon sprouting and syntagmatic relation of neuron in the anterior horn of gray matter above lesion were observed by immunofluorescence double-labeling of BDA/neuron-specific nuclei protein (NeuN); the expression of Synapsin in the anterior horn of gray matter at lesion was observed by immunofluorescence double-labeling of NeuN/Synapsin I. Results:Eight weeks after injury, the latency of P1 and N1 was longer in the model group than in the sham group (P < 0.05), and was shorter in the training group than in the model group (P < 0.05). Compared with the sham group, the error rate of left forelimb increased, and the usage rate decreased (P < 0.05) in the model group and the training group; compared with the model group, the error rate of left forelimb decreased six weeks and eight weeks after injury (P < 0.05), and the usage rate increased eight weeks after injury (P < 0.05) in the treatment group. Compared with the model group, more axon sprouting co-localized with neurons in the anterior horn of gray matter above lesion (P < 0.05), and the expression of Synapsin I increased in the training group (P < 0.05). Conclusion:Task-based rehabilitative training could promote the neural circuit plasticity and improve the motor function of forelimb after spinal cord injury in mice.

Neuronal Activity in the Cerebellum During the Sleep-Wakefulness Transition in Mice / 神经科学通报·英文版

Cerebellar malfunction can lead to sleep disturbance such as excessive daytime sleepiness, suggesting that the cerebellum may be involved in regulating sleep and/or wakefulness. However, understanding the features of cerebellar regulation in sleep and wakefulness states requires a detailed characterization of neuronal activity within this area. By performing multiple-unit recordings in mice, we showed that Purkinje cells (PCs) in the cerebellar cortex exhibited increased firing activity prior to the transition from sleep to wakefulness. Notably, the increased PC activity resulted from the inputs of low-frequency non-PC units in the cerebellar cortex. Moreover, the increased PC activity was accompanied by decreased activity in neurons of the deep cerebellar nuclei at the non-rapid eye-movement sleep-wakefulness transition. Our results provide in vivo electrophysiological evidence that the cerebellum has the potential to actively regulate the sleep-wakefulness transition.

Expression of Neuroligin1 after Spinal Cord Injury in Rats / 中国康复理论与实践

Objective To observe the change of expression of neuroligin1 (NL1) in injured spinal cord in rats. Methods A total of 60 adult female Sprague-Dawley rats were randomly divided into control group (n=30) and experi-ment group (n=30), and both groups were further arranged into three days, seven days, 14 days, 21 days, and 28 days subgroups. The control group accepted T9-11 laminectomy, while the experiment group was injured at T10 spi-nal cord hit by Allen's technique (10 g×25 mm). They were assessed with Basso, Beattie & Bresnahan locomotor rating scale (BBB scale), in their time-points, while Golgi-Cox staining was used to observe the variation of den-drites and density of dendritic spine in the white matter located at upper end of spinal cord injured center, and im-munofluorescence staining was used to detect the expression of NL1. Results The score of BBB scale reduced in the experiment group compared with that in the control group in every sub-group (P<0.001). Compared to the control group, both dendrites and density of dendritic spine in the white mat-ter decreased with time after injury (P<0.001), while the level of NL1 increased three days after injury, peaked on the 14th day after injury (P<0.05). Conclusion NL1 increases spontaneously after spinal cord injury, but it is not enough to promote synaptic regeneration.

Prenatal diagnosis of a fetus in a family with mandibulofacial dysostosis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To measure the feasibility of application of comparative genomic hybridization technique in the prenatal diagnosis of fetus with mandibulofacial dysostosis.</p><p><b>METHODS</b>A pregnant woman having a fetus with mandibulofacial dysostosis diagnosed by prenatal ultrasound test was selected. The amniotic fluid and blood of the pregnant and blood of her husband were collected and conventional cytogenetic analysis was performed. The whole genome was scanned by array comparative genomic hybridization assay (array-CGH). Reverse transcription fluorescence quantitative PCR (RT-qPCR) analysis was used to verify the result of array-CGH.</p><p><b>RESULTS</b>No abnormality was found in conventional cytogenetic analysis while a duplicated region in 1p36.33 was detected by array-CGH assay. The region spans 722 kb and contains two genes, VWA1 and PYGO2, which play roles in the development of cartilage. The result of array-CGH was confirmed by the RT-qPCR assay. The diagnosis of mandibulofacial dysostosis was confirmed after birth.</p><p><b>CONCLUSION</b>Author diagnosed a fetus with mandibulofacial dysostosis by array-CGH assay and found two candidate genes related to the development of craniofacial bone: VWA1 and PYGO2.</p>

Analysis of Down syndrome screening by maternal serum detection in mid-pregnancy / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the clinical value of screening chromosomal diseases and abnormal pregnancy by maternal serum examination in mid-pregnancy.</p><p><b>METHODS</b>Maternal serum AFP and F-beta hCG were detected in the mid-pregnancy (16-20 weeks) using commercially available detection kits, and the risk of Down syndrome was calculated taking into account of such factors as the maternal age, gestational age, and body weight. Those at high risk underwent amino fluid or cordocentesis for fetal karyotpying. The pregnant women were divided into >or=35 years and <35 years groups, and high and low risk for Down syndrome groups for test results and pregnancy outcome analysis.</p><p><b>RESULTS</b>Of the 6000 pregnant women undergoing antenatal screening, 552 were identified to be at high risk of Down syndrome (9.2%) with one missing case of detection, and 463 of the high-risk cases underwent amino fluid or cordocentesis examination. Twenty-seven cases were found to have abnormal chromosomes, and abortion was suggested in 14 cases but not in the other 13 cases where other chromosomal abnormalities such as polymorphic mutations were found. The screening positive rate in >or=35 years and <35 years group was 95.5% and 8.2% (P<0.0001), with fetal chromosomal abnormality rate of 4.5% and 2.9%, respectively (P>0.5). The rate of abnormal pregnant outcomes for high and low risk groups was 5.6% and 0.05% (P<0.0001), with pregnancy complication rate of 11.8% and 3.7% (P<0.0001) and fetal chromosomal polymorphic mutation rate of 2.8% and 1.1% (P>0.5), respectively.</p><p><b>CONCLUSION</b>Maternal serum AFP and F-beta hCG levels in second trimester have important values in predicting fetal chromosomal diseases, and their detection may help reduce the birth defect rate and prevent abnormal pregnancy outcomes and complications.</p>

Experimental study of electrophysiologic effects of regenerative nerve fibres affected by control releasing FK506 / 中国骨伤

<p><b>OBJECTIVE</b>To discuss the electrophysiologic effects of regenerative nerve fibres affected by control releasing of FK506.</p><p><b>METHODS</b>From Mar. to Sep. in 2008, the body weigh of 32 Sprague-Dawley rats which was 200 to 250 g,anesthesia was performed with an intraperitoneal injection of 30 mg/kg 1% continal. The sciatic nerve was transected in each rat by the excision of a 10 mm gap just proximal to the trifurcation of the nerve. The 10 mm gap of sciatic nerve had been bridged with the new double channel nerve conduit of fusiform shape, which were randomly divided into two groups basing on the different drug in the channel, each group contained 16 animals. In group A,100 microl of chitin for medical use was injected into the conduit,in group B the two branches of the conduit respectively contained 100 microl of the chitin and 10 microl FK506 (group B2) or physiologic saline (group B1). At 8 and 12 week after operation, the morphology in regenerative nerve and electrophysiologic effects by detect compound muscle active potential (CMAP) and cortical somatosensory evoked potential (CSEP) were evaluated.</p><p><b>RESULTS</b>There were not significant differences of the regenerative nerve fibres between two channels in group A, but in group B2, the number of the regenerative fibres was much more than that in group B1. The latency of CMAP and CSEP in group B2 was shorter than that in group B1. But its amplitude was higher. There were highly significant difference between the groups (P < 0.01).</p><p><b>CONCLUSION</b>The electrophysiologic effects of regenerative nerve fibres can be significantly promoted by FK506, which provide theory base for immunosuppressive treatment of peripheral nerve.</p>

A clinical analysis of fetal chromosomal aberration induced by paint and hair dye / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the effect of long-term exposure to paint or hair dye on chromosomal aberration of early embryos.</p><p><b>METHODS</b>We analyzed 2 cases of fetal or infantile chromosome aberration in which the parents experienced long-term exposure to paint and hair dye.</p><p><b>RESULT</b>The chromosomal mutations were detected in one 3-month-old infant and one 21-week-old fetus, and the karyotypes were 46,XX,del(2)(pter'q31) and 46,XX, t(4;12;15), respectively. Their parents worked with long-term exposure to paint and hair dye and developed such symptoms as dizziness, headache, and insomnia. The chromosomes of the parents remained normal, but the micronuclei of the lymphocytes and plasma lead level were increased with decreased WBC, platelet, and HGB.</p><p><b>CONCLUSION</b>Long exposure to paint or hair dye can cause poison and affect the normal growth of early embryos, leading eventually to gene and chromosomal mutation of the embryos.</p>

Changes of peripheral blood chromosomal centromere aberration in patients with cytomegalovirus infection after anti-viral treatment / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the changes of peripheral blood chromosomal centromere aberration in patents with cytomegalovirus (CMV) infection after anti-viral treatment.</p><p><b>METHODS</b>Sixty-two patients with early spontaneous abortion and CMV infection analyzed for their peripheral blood chromosomal centromere using simultaneous silver staining before and after anti-viral treatment.</p><p><b>RESULTS</b>The patients with CMV infection had high rate of centromere aberration, which was decreased significantly after anti-viral treatment (P<0.0001).</p><p><b>CONCLUSION</b>CMV infection is a risk factor for peripheral blood chromosomal centrimere aberration. Anti-viral treatment can decrease the rate of centrimere aberration aberration. Detection of peripheral blood chromosomal centrimere aberration allows the assessment of the severity of infection and the condition after treatment.</p>

Identification of a novel regeneration-related gene H3 and its protein from the differential expression cDNA library of spinal cord injury in neonatal rats / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To clone and identify one novel regeneration related gene H(3) (CA854305) from the differential expression genes library we had set up before.</p><p><b>METHODS</b>Use the method of Northern blot to detect the different expressions of the novel gene under different situations, employ the technique of in silico cloning to scan the span of the novel gene, and analyze their sequences. Also we used reverse transcription PCR to validate the largest open reading frame.</p><p><b>RESULTS</b>Northern blotting results of H(3) (CA854305) showed that the transplanted group had more efficient and extensive expression than untreated and uninjured groups 5 days after spinal cord injury, while the untreated group had more extensive expression than uninjured group. It implied that H(3) might have some relationship with nerve regeneration after spinal cord injury. From the results of in silico cloning we got a longest contig of 1635 bp and an largest open reading frame of 542 bp from 49 to 591 bp correspondent with the Cozak rules. Reverse transcription PCR validated the largest open reading frame sequence primarily.</p><p><b>CONCLUSIONS</b>We got the sequence of novel gene H(3) which might be one of the regenerationjrelated genes. Key words:Gene library; Genes; Nerve regeneration; Spinal cord injuries.</p>

The difference of nerve growth factor and ciliary neurotrophic factor between the sensitive and motor fibres regeneration / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the effects of nerve growth factor (NGF) and ciliary neurotrophic factor (CNTF) to promoting the sensitive and motor fibres regeneration.</p><p><b>METHODS</b>Thirty two Sprague-Dawley rats with 10 mm gap of sciatic nerve were operated and bridged with the new double channel nerve conduit in rhomboid shape. They were randomly divided into two groups, with each in twelve animals. In the first group, 200 micro1 of chitin for medical use was injected into the conduit, and in the second group the two branches of the conduit contained 100 microl of the chitin and 5 microl NGF or CNTF. At twelve and sixteen weeks after the operation, we evaluated the sensitive and motor fibres of regenerative nerve with Holmes, Acetylcholinesterase and Carbonic anhydrase staining.</p><p><b>RESULTS</b>After the twelve and sixteen weeks of the operation, there were not significant differences of the regenerative nerve fibres between two channels in the first groups. But in the second group, the number of the motor fibres of the regenerative nerve of CNTF branch channel was much more and distributed better than the others, while the number and density of sensitive fibres was inferior to NGF. The latency of compound muscle active potential and cortical somatosensory evoked potential of the nerve in the CNTF branch was shorter than the one in the NGF branch, but its amplitude was higher.</p><p><b>CONCLUSIONS</b>The CNTF could significantly promote the regeneration of motor fibres and the NGF could promote better for the regeneration of sensitive fibres.</p>

Spontaneous discharges of pyramidal cells in the dorsal hippocampus of guinea pig / 生理学报

To determine the characteristics of spontaneous discharges of hippocampal pyramidal cells (PCs), extracellular neuronal firing in CA1 and CA3 regions of dorsal hippocampus was recorded, the firing modes and interspike interval (ISI) were analyzed with the conventional and nonlinear methods. PCs were discriminated from interneurons using the measurement of action-potential duration and firing rate in this study. There was no significant difference in duration, mean firing frequency, complexity and firing mode between the neurons in CA1 and CA3 regions both in anesthetized and awake animals. The complexity of neurons was higher in awake group than that in anesthetized group, though no difference was found in firing rate. There were differences in the type of pyramidal cells and the coefficient of variance of ISI of neurons. The results obtained from the spontaneous discharges of dorsal hippocampal pyramidal cells reveal some nonlinear and linear aspects in anesthetized and awake states. It seems likely that the combination of conventional and non-linear measurements of the hippocampal pyramidal cells encoding may reflect genuine characteristics of the hippocampal pyramidal cells.