1.RATE OF REGENERATION OF DAMAGED SPINAL AXONS INTO PERIPHERAL NERVE GRAFTS IN ADULT RAT
Siwei YOU ; Gong JU ; Jielai XIA
Acta Anatomica Sinica 1955;0(03):-
Cho and So studied, with horseradish peroxidase retrograde tracing technique, the initial delay time and the rate of regrowth of damaged retinal ganglion cell axons regenerating into the autologous sciatic nerve implanted into the retinae in adult hamsters. This is the only report, to our knowledge, on the rate of regeneration of damaged central neuron axons. The present experiment tackles this issue using autologous sciatic nerve transplantation into the dorsal horn of the damaged spinal cord in adult rats, a model introduced by David and Aguayo, and visualized the regenerating axons with anti-neurofilament monoclonal antibody immunohistochemical method. Our results are as follows: the minimum initial delay time of the regenerating spinal axons in peripheral nerve grafts is 4 days. After which axons continue to regrow into the grafts within a definite period, suggesting different initial delay time for different regenerating axons. The regenerating spinal axons differ in their rate of regrowth, the fastest rate being 2.14 mm/d.
2.EFFECT OF DISTANCE OF AXOTOMY ON AXONAL REGENERATION OF RETINAL GANGLION CELLS INTO A NORMAL OR PRE-DEGENERATED PERIPHERAL NERVE GRAFT IN ADULT HAMSTERS
Siwei YOU ; Guohui SU ; Jiaxun YE
Acta Anatomica Sinica 1953;0(01):-
Objective\ The present study was carried out to examine the relationship between the distance of axotomy and axonal regeneration systematically,and the effect of a pre\|degenerated peripheral nerve(PN) graft on axonal regeneration of retinal ganglion cells(RGCs) axotomized at different distances. Methods\ The optic nerve(ON) was transected at 0\^5,1,1\^5,2,3 or 7mm from the optic disc and a normal (the normal group) or pre\|degenerated(the pre\|degeneration group) PN graft was transplanted onto the ocular ON stump in adult hamsters. Results\ In both groups,the number of regenerating RGCs 28 days after grafting decreased significantly when the distance of axotomy increased from 0\^5 to 7mm with a sharp decline between 0\^5 and 3mm.When the corresponding distance points between the two groups were compared,enhanced regeneration was observed at 2 and 3mm in the pre\|degeneration group. Conclusion\ These results show that the distance of axotomy on the ON of adult hamsters is critical in determining the number of regenerating RGCs.The beneficial effect of a pre\|degenerated PN graft on axonal regeneration of axotomized RGCs is conditional on the distance of axotomy.\;
3.cAMP induces axonal regeneration in spinal cord injury of rats
Xiangrong CHEN ; Hui JIANG ; Siwei YOU
Chinese Journal of Orthopaedics 2001;0(05):-
Objective cAMP promotes neurite outgrowth in vitro. The study is aimed to understand whether cAMP can repair spinal cord injury of rats. Methods 56 rats models of spinal cord hemisection were adopted and randomly distributed into six groups. Dibutyryl-cAMP or physiological saline was injected either once in the motor cortex with an amount of 6 ml of 50 mmol/L cAMP, or continuously infused through a polyethylene tube connecting with a micro-pump in the spinal lesion area or in the subarachnoid space with a total amount of 72 ml of 10 mmol/L cAMP for 72 h. The distribution of neurofilament (NF) in the lesion area was observed by immunohistochemistry. Corticospinal tracts (CST) and spinal axons regeneration were investigated by CST and spinal axons anterograde tracing with biotinylated dextran amine (BDA). The function of hindlimb movements were evaluated by BBB scales and as a reference to assess the repairing effect of treating strategy. Results NF were densely distributed and extended in the lesion area in the cAMP groups, but no connection could be found with the NF in the caudal. No axonal regeneration could be achieved when cAMP was input into the subarachnoid space. Many regenerated axons, including some CST axonal regeneration were presented in the lesion areas in cAMP groups though no continuous long regenerated axons traversed the lesion area, while there was no regenerated axon in the lesion areas in the control groups. All the rats restored to normally walk 4 to 5 weeks after operations, BBB scale exceed 20, and no significant difference between cAMP groups and control groups by comparing the BBB scales of hindlimb movements. Conclusion cAMP injected in the brain cortex or continuously infused in the spinal lesion area can induce the axonal regeneration and is beneficial to repair the spinal cord injury, but could not directly promote hindlimb movements recovering.
4.EXPRESSION OF HUMAN CNTF MEDIATED BY RETROVIRAL VECTOR IN OLFACTORY ENSHEATHING CELLS in vitro AND EFFECTS ON NEURONAL SURVIVAL AND NEURITE OUTGROWTH
Hao YANG ; Weilin JIN ; Ming FAN ; Siwei YOU ; Gon JU
Acta Anatomica Sinica 1957;0(04):-
Objective To explore the effects of expressing human ciliary neurotrophic factor (hCNTF) mediated by retroviral vector in olfactory ensheathing cells(OECs) on the survival and neurite outgrowth of cultured neurons. Methods S\|hCNTF fragment was digested with endonucleases(Kpn I and Xba I) from pcDNA\-3\|S\|hCNTF plasmid and cloned into pRev\|TRE vector.The harvested pRev\|TRE\|hCNTF was identified and transfected with pRev\|Tet\|On into ecotropic Ecopack\|293 cells,resulting in 2 retroviral supernatants(pRev\|TRE\|hCNTF and pRev\|Tet\|On).Primarily cultured rat olfactory ensheathing cells(OECs) were co\|infected with the 2 retroviruses,and induced to secrete hCNTF with different concentrations of doxycline.The secreted hCNTF in OEC culture supernatant was detected with Western\|blot.Dorsal root ganglion (DRG) from a postnatal rat of 2 days was co\|cultured with CNTF\|modified OECs,and the supernatant was used to culture retinal ganglion cells(RGCs).Following ?\|tubulin immunocytochemical staining,the length of DRG neurites were measured,while the numbers of surviving RGCs were counted. Results 1.Individual 630bp and 400bp fragments were digested from pRev\|TRE\|S\|hCNTF expression vector with endonucleases(Hind Ⅲ and BamH Ⅰ),and respected direction and integration of hCNTF cDNA which inserted pRev\|TRE vector were identified; 2.The expression of 24kD CNTF proteins in CNTF\|modified OEC culture supernatant was positively\|correlated with the concentration of doxycline,while no such protein expression was detected in the control groups; 3.The number of surviving RGCs in CNTF\|modified OECs group(41\^34?5\^4) was significantly higher than those in unmodified OEC(23\^15?4\^7),OECs(24\^55?5\^8) and blank(16\^8?6\^5) groups;and 4\^The neurites of DRG were longer (660?67?m) and denser in CNTF\|modified OECs group,as compared with unmodified OECs(418?45?m),Mock+OECs(400?65?m) and blank (0?m) control groups.No process migrated and grew from the tissue mass in blank group.Conclusion\ hCNTF can be expressed in OECs with a doxycline concentration\|dependent manner after transfected via pRev\|TRE\|S\|hCNTF vector,and possesses a marked enhancing effect on the survival and neurite outgrowth of cultured neurons.[
5.Urgent requirements for clinical translational studies in restoration of injured optic nerve
Siwei YOU ; Dan HU ; Yusheng WANG
Chinese Journal of Ocular Fundus Diseases 2017;33(6):569-572
The optic nerve belongs to the central nervous system (CNS).Because of the lack of neurotrophic factors in the microenvironment of the CNS and the presence of myelin and glial scar-related inhibitory molecules,and the inherent low renewal potentials of CNS neurons comparing to the peripheral nerve system,it is difficult to spontaneously regenerate the optic nerve after injury.Protecting damaged retinal ganglion cells (RGCs),supplementing neurotrophic factor,antagonizing axon regeneration inhibitory factor,and regulating the inherent regeneration potential of RGCs can effectively promote the regeneration and repair of optic nerve.Basic research has made important progress,including the restoration of visual function,but there are still a lot of unsolved problems in clinical translation of these achievements,so far there is no ideal method of treatment of optic nerve injury.Therefore,it is rather urgent to strengthen the cooperation between basic and clinical research,to promote the transformation of basic research to the clinical applications as soon as possible,which will change the unsatisfactory clinical application status.
6.Observation of 4 patients with positive anti-glial fibrillary acidic protein antibody
Yanru HE ; Ying LIU ; Siwei YOU
Chinese Journal of Ocular Fundus Diseases 2023;39(11):898-903
Objective:To observe the clinical characteristics of the patients with positive anti-glial fibrillary acidic protein (GFAP) antibody.Methods:A retrospective study. From January 2017 through December 2021, 4 patients with positive anti-GFAP antibodies hospitalized in Departments of Ophthalmology and Neurology of Xijing Hospital, Air Force Medical University were included in this study. There were 3 patients with optic neuritis (ON) and 1 patient with the spinal and cerebral lesions. All patients were female, with an average age of 35 years. Three patients with ON received the examinations of best corrected visual acuity (BCVA), optical coherence tomography, visual evoked potential and magnetic resonance imaging (MRI) for the head and orbital. Another 1 patient with the spinal and cerebral lesions underwent MRI for the head, cervical and thoracic vertebras. All patients were tested for demyelinating ON-related antibodies in the serum, and the patient with the spinal and cerebral lesions for the antibodies in both serum and cerebrospinal fluid. Patients with ON received intravenous infusion of methylprednisolone sodium succinate in the acute stage, while the patients with spinal cord and brain lesions were given glucocorticoid and immunosuppressive therapy.Results:The initial symptoms of the patients with ON were sudden blurred vision in the right eye together with a pain when the eye rotated. BCVA were hand moving/in-front, 0.2 and 0.12, respectively. The serum anti-GFAP antibodies were positive. MRI showed a rough and thickened optic nerve in 1 patient. For patients with BCVA of hand moving/in-front, the BCVA was increased to counting fingers/30 cm on discharge; while the other 2 patients had no changes for BCVA. When followed up on phone 2-3 years after discharge, BCVA of the patients with ON increased to higher than 0.6. No ocular symptoms occurred in the patient with spinal and cerebral lesions and his initial symptoms were numbness, weakness and convulsions of limbs, accompanied by slurred speech. His anti-GFAP antibodies in the serum were negative but positive in the cerebrospinal fluid. MRI showed enhanced cerebellum and spinal dura mater. The initial symptoms were relieved on discharge, and vanished when followed up on phone after discharge.Conclusions:The patients with positive anti-GFAP antibodies are more common in young and middle-aged women. Monocular optic neuritis is more often seen in the form of sudden blurred vision with an eye-rotating pain. Anti-GFAP antibodies in the serum are positive, and a few patient show a rough and thickened optic nerve. They are sensitive to glucocorticoid therapy with a satisfied prognosis.
7.Protective effect of etomidate on cultured retinal ganglion cells with mechanical injury in vitro
Xuan ZHAO ; Jue BAI ; Siwei YOU ; Yuanyuan CUI ; Mingmei WU
Chinese Journal of Ocular Fundus Diseases 2023;39(6):489-493
Objective:To observe the protective effect of etomidate (ET) on cultured retinal ganglion cells (RGC) with mechanical injury in vitro.Methods:New Sprague-Dawley rat RGC was cultured in vitro and identified by double immunofluorescent labeling of Thy1.1 and microtubule associated protein 2. The cultured primary cells were randomly divided into control group, RGC scratch group, ET low dose group (1 μmol/L), ET medium dose group (5 μmol/L) and ET high dose group (10 μmol/L). The RGC mechanical injury model was established by using iris knife to culture cells in RGC scratch group and ET group with different concentration. Seven days after modeling, the RGC survival rate of each group was detected by cell count Kit 8 proliferation assay. The apoptosis rate of RGC was detected by Annexin Ⅴ/propyl iodide double staining. Single factor analysis of variance was used to compare the groups. The pairwise comparison between groups was tested by the least significant difference method.Results:The survival rates of RGC in RGC scratch group, ET low dose group, ET medium dose group and ET high dose group were (72.60±2.97)%, (73.73±1.14)%, (79.19±1.79)% and (83.88±0.94)%, respectively. The RGC apoptosis rates of control group, RGC scratch group, ET low dose group, ET medium dose group and ET high dose group were (5.08±0.17)%, (18.67±1.24)%, (17.96±0.74)%, (15.11±0.56)% and (11.67±1.32)%, respectively. Comparison of RGC survival rate between groups: compared with RGC scratch group, the cell survival rate of ET low-dose group, ET medium-dose group and ET high-dose group was increased, and the difference between RGC scratch group and ET low-dose group was not statistically significant ( P=0.728); the differences between RGC scratch group, ET medium dose group and ET high dose group were statistically significant ( P<0.001); the difference between ET medium dose group and ET high dose group was statistically significant ( P=0.002). Comparison of apoptosis rate of RGC among groups: the apoptosis rate of RGC scratch group was significantly higher than that of control group, the difference was statistically significant ( P<0.001). Compared with RGC scratch group, the apoptosis rate of ET low-dose group, ET medium-dose group and ET high-dose group was decreased, and there was no statistical significance between RGC scratch group and ET low-dose group ( P=0.869). The differences of apoptosis rate between RGC scratch group, ET medium dose group and ET high dose group were statistically significant ( P<0.05). The difference of apoptosis rate between ET medium dose group and ET high dose group was statistically significant ( P=0.007). Conclusion:ET has neuroprotective effect on RGC cultured in vitro with mechanical injury, and the protective effect increases with the increase of ET dose in a certain range.
8.Effects of antenatal dexamethasone and postnatal pulmonary surfactant combined with respiratory support on lung fluid clearance in preterm rabbits
Xiaohan YOU ; Li MA ; Huibo AN ; Siwei LUO ; Yaling XU ; Xiaojing GUO ; Bo SUN
Chinese Journal of Perinatal Medicine 2023;26(4):315-324
Objective:To explore the effects of prenatal dexamethasone (DEX), postnatal pulmonary surfactant (PS) and respiratory support on the lung fluid clearance in premature rabbits at gestational age (GA) of 25-28 d (full term: 31 d) and their relationship with dynamic compliance of respiratory system (Cdyn), pulmonary morphology and other parameters.Methods:In our previous publications, premature rabbits were divided into four groups according to the intervention strategy: control group, PS-only group, DEX-only group and DEX+PS group in which data of several parameters including wet-to-dry lung weight ratio (W/D), Cdyn and volume density of alveoli (Vv) were retrieved and the lung tissue sections were scanned to recalculate the ratio of perivascular sheath to vascular sectional area (S/V) and lung injury scores-edema (LIS-E). W/D, LIS-E, S/V and Vv were adjusted for birth weight (BW) (divided by BW, represented as W/D/BW, LIS-E/BW, S/V/BW and Vv/BW) and mean Cdyn (Cdyn-m) was adopted. Based on the grouping of previous studies, the intervention groups in this study were divided as DEX group and non-DEX group, and PS group and non-PS group to analyze the influence of DEX and PS on the above parameters. Two independent samples t-test, one-way analysis of variance, LSD test, Kruskal-Wallis H test, Mann-Whitney U test and Pearson correlation analysis were used for statistical analysis. Results:A total of 196 newborn rabbits receiving mechanical ventilation after birth were included in this study. (1) Effects of DEX: compared with the non-DEX group, the DEX group showed increased W/D/BW (489±69 vs 421±113, t=-2.09), LIS-E/BW (188±57 vs 138±55, t=-2.61) and Vv/BW (20.1±4.9 vs 14.2±4.7, t=-3.60), but decreased S/V (0.33±0.23 vs 0.51±0.25, t=2.23) and S/V/W/D (0.05±0.03 vs 0.07±0.04, t=2.22) at 25 d of gestation; at 26 d of gestation, W/D/BW (472±76 vs 303±44, t=-8.75), LIS-E/BW (189±63 vs 106±36, t=-5.23), Cdyn-m [(0.16±0.07) vs (0.05±0.03) ml/(kg?cmH 2O), 1 cmH 2O=0.098 kPa; t=-7.29] and Vv/BW increased (22.4±5.0 vs 12.2±3.8, t=-7.46), while S/V (0.23±0.19 vs 0.62±0.38, t=4.10), S/V/BW (15.7±12.4 vs 25.7±17.3, t=2.20), S/V/W/D (0.03±0.03 vs 0.08±0.05, t=3.92) and propensity scores decreased [(12.5±1.2) vs (15.1±1.2) scores, t=7.00]; at 27 d of gestation, Cdyn-m increased [(0.23±0.12) vs (0.16±0.07) ml/(kg?cmH 2O), t=-2.43], but S/V (0.32±0.23 vs 0.57±0.39, t=2.57) and S/V/W/D decreased (0.05±0.04 vs 0.09±0.06, t=2.55); at 28 d of gestation, W/D/BW (270±64 vs 162±33, t=-8.09), LIS-E/BW (72±32 vs 35±20, t=-5.17), S/V (0.90±0.60 vs 0.59±0.48, t=-2.81), S/V/BW (34.0±23.6 vs 15.2±12.7, t=-3.77) and Vv/BW increased (16.9±4.3 vs 9.2±2.9, t=-8.04); the differences were all statistically significant (all P<0.05). (2) Effects of PS: compared with the non-PS group, the PS group had decreased LIS-E/BW at 25, 26 and 27 d of gestation, increased Cdyn-m and Vv/BW at 25 and 27 d of gestation and higher propensity scores at 25 d of gestation (all P<0.05). (3) The correlation between gestational age and each index: gestational age was positively correlated with S/V ( r=0.31, P<0.05), but negatively correlated with W/D/BW and LIS-E/BW ( r=-0.73 and-0.63, both P<0.05). Conclusions:The pharmacological action of prenatal DEX on lung fluid clearance is mainly confined to preterm rabbits at the GA of 28 d which is supported by mechanical ventilation. Prenatal treatment with DEX and/or postnatal PS can improve the early respiratory function in preterm rabbits between GA of 25-27 d, but had no substantial impact on lung fluid clearance. The GA-related lung maturation appears to play a crucial role, in comparison with medications, in lung fluid clearance.
9. Development and validation of a method for quantitation of cefepime/avibactam in M-H broth: application to antibacterial activity using in vitro PK/PD Model
Bingqian YAN ; You LI ; Miaomei TIAN ; Bingqian YAN ; Siwei GUO ; You LI ; Miaomei TIAN ; Bing XU ; Rong JIANG ; Xin LI ; Siwei GUO ; Bing XU ; Rong JIANG ; Xin LI
Chinese Journal of Clinical Pharmacology and Therapeutics 2024;29(1):52-60
AIM: To establish a method for quantitation of cefepime and avibactam in M-H broth, and applicated in the in vitro dynamic PK/PD model. METHODS: The cefepime was also determined using the high-performance liquid chromatography method (HPLC), the avibactam was also determined using the liquid chromatography-mass spectrometry (LC-MS/MS), an in vitro dynamic PK/PD model was established to study the PK/PD relationship of cefepime/avibactam against carbapenem resistant Klebsiella pneumoniae (CRKP). RESULTS: The linear ranges of cefepime and avibactam were good at (0.5-20) and (0.1-25) μg/mL (r=0.999), and the lower limit concentrations were 0.5 and 0.1 μg/mL. The extraction recoveries of cefepime and avibactam in M-H broth were 88.0%-101.7% and 90.9%-95.2%, the relative standard deviation of intra-day precision and inter-day precision were less than 5.2%. The concentration-time curves were well simulated by the PK/PD model. All observed concentrations in each experiment were in the range of 20% of the targeted values. For the CRKP of MIC=8 μg/mL and MIC=16 μg/mL, the colony decreased to 2.783Log10 CFU/mL and 1.325Log10 CFU/mL at the cefepime/avibactam 2.5 g q8 h administration after 24 h. CONCLUSION: The determination method of cefepime and avibactam in broth established in this study has high sensitivity and good stability. For the CRKP with MIC≤8 μg/mL,cefepime/avibactam showed that good anti-CRKP activity under routine administration in vitro dynamic PK/PD model.
10.Mutational Signatures Analysis of Micropapillary Components and Exploration of ZNF469 Gene in Early-stage Lung Adenocarcinoma with Ground-glass Opacities.
Youtao XU ; Qinhong SUN ; Siwei WANG ; Hongyu ZHU ; Guozhang DONG ; Fanchen MENG ; Zhijun XIA ; Jing YOU ; Xiangru KONG ; Jintao WU ; Peng CHEN ; Fangwei YUAN ; Xinyu YU ; Jinfu JI ; Zhitong LI ; Pengcheng ZHU ; Yuxiang SUN ; Tongyan LIU ; Rong YIN ; Lin XU
Chinese Journal of Lung Cancer 2024;26(12):889-900
BACKGROUND:
In China, lung cancer remains the cancer with the highest incidence and mortality rate. Among early-stage lung adenocarcinomas (LUAD), the micropapillary (MPP) component is prevalent and typically exhibits high aggressiveness, significantly correlating with early metastasis, lymphatic infiltration, and reduced five-year survival rates. Therefore, the study is to explore the similarities and differences between MPP and non-micropapillary (non-MPP) components in malignant pulmonary nodules characterized by GGOs in early-stage LUAD, identify unique mutational features of the MPP component and analyze the relationship between the ZNF469 gene, a member of the zinc-finger protein family, and the prognosis of early-stage LUAD, as well as its correlation with immune infiltration.
METHODS:
A total of 31 malignant pulmonary nodules of LUAD were collected and dissected into paired MPP and non-MPP components using microdissection. Whole-exome sequencing (WES) was performed on the components of early-stage malignant pulmonary nodules. Mutational signatures analysis was conducted using R packages such as maftools, Nonnegative Matrix Factorization (NMF), and Sigminer to unveil the genomic mutational characteristics unique to MPP components in invasive LUAD compared to other tumor tissues. Furthermore, we explored the expression of the ZNF469 gene in LUAD using The Cancer Genome Atlas (TCGA) database to investigate its potential association with the prognosis. We also investigated gene interaction networks and signaling pathways related to ZNF469 in LUAD using the GeneMANIA database and conducted Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Lastly, we analyzed the correlation between ZNF469 gene expression and levels of immune cell infiltration in LUAD using the TIMER and TISIDB databases.
RESULTS:
MPP components exhibited a higher number of genomic variations, particularly the 13th COSMIC (Catalogue of Somatic Mutations in Cancer) mutational signature characterized by the activity of the cytidine deaminase APOBEC family, which was unique to MPP components compared to non-MPP components in tumor tissues. This suggests the potential involvement of APOBEC in the progression of MPP components in early-stage LUAD. Additionally, MPP samples with high similarity to APOBEC signature displayed a higher tumor mutational burden (TMB), indicating that these patients may be more likely to benefit from immunotherapy. The expression of ZNF469 was significantly upregulated in LUAD compared to normal tissue, and was associated with poor prognosis in LUAD patients (P<0.05). Gene interaction network analysis and GO/KEGG enrichment analysis revealed that COL6A1, COL1A1, COL1A2, TGFB2, MMP2, COL8A2 and C2CD4C interacted with ZNF469 and were mainly involved in encoding collagen proteins and participating in the constitution of extracellular matrix. ZNF469 expression was positively correlated with immune cell infiltration in LUAD (P<0.05).
CONCLUSIONS
The study has unveiled distinctive mutational signatures in the MPP components of early-stage invasive LUAD in the Asian population. Furthermore, we have identified that the elevated expression of mutated ZNF469 impacts the prognosis and immune infiltration in LUAD, suggesting its potential as a diagnostic and prognostic biomarker in LUAD.
Humans
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Lung Neoplasms/genetics*
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Adenocarcinoma of Lung/genetics*
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China
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Prognosis
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Transcription Factors