BACKGROUND:The nervous reconstruction and repair after spinal cord injury have become a research hotspot.
OBJECTIVE:To investigate the change rule of neurogliocyte reactive hyperplasia after spinal cord injury.
METHODS:Forty-two adult male Sprague-Dawley rats were selected and equivalently randomized into seven groups:normal control group (no intervention), sham operation group (lamina decompression) and operation groups (postoperative 1, 7, 14, 21 and 28 days). After the establishment of spinal cord injury models, the rats were sacrificed at each corresponding time point. The functional recovery of the rat hind limbs was evaluated by Basso, Beattie and Bresnahan scores, and complete spinal cord tissue was removed to undergo hematoxylin-eosin staining, immunohistochemistry staining and immunofluorescence staining.
RESULTS AND CONCLUSION:(1) Basso, Beattie and Bresnahan scores showed that rats in the normal control and sham operation groups had normal neurologic function. Rats at 1 day after spinal cord injury paralyzed completely, the neurologic function of hind limbs began to recover gradual y at the 7th day, and the recovery became most obvious at the 14th day, which had no significant differences compared with the 21st and 28th days. (2) Hematoxylin-eosin staining found that the diffuse hemorrhage and neuronal necrosis were observed in the injured area at 1 day after operation;inflammatory cel infiltration and some vacuoles appeared at the 7th day, and the hemorrhage was absorbed gradual y;the hemorrhage disappeared completely and capsule cavity formed at the 14th day;up to the 28th day, spinal cord structure was completely destroyed and that was replaced by cicatricial tissue accompanying with a large cavity. (3) Immunohistochemistry staining showed that the astrocyte in damaged area proliferated with the cel synapse increasing, which was most overt at the14th day;the axon clearance widened and the structure was in disorder at the 7th day, and the myelin sheath in the damaged area was destroyed at the 21st day. (4) Immunofluorescence staining showed that there were numerous visible glial fibril ary acidic protein+/nestin+cel s in the injured area at 14 days after operation. (5) These results suggest that glial cel hyperplasia and hypertrophy, the up-regulated expressions of glial fibril ary acidic protein and nest protein are advantageous to the early repair of spinal cord injury.

BACKGROUND:Human mesenchymal stem cells derived from Wharton's jelly(WJCs)display the characteristics of MSCs as defined by the International Society for Cellular Therapy.They can be differentiated into bone,cartilage,adipose,muscle,and neural cells.They can also support the expansion of other stem cells,be weli-tolerated by the immune system,and have the ability to home to tumors.OBJECTIVE:To investigate biological changes of WJCs and brain tumor stem cells(BTSCs)co-cultured in vitro.METHODS:WJCs cultured by situ cultivation and BTSCs used enzyme digestion way respectively,and gathering the 3rd passage of WJCs though subculturing as well as BTSCs.Two kinds of cells co-cultured in 24-well plates in serum-free medium (SFM)without any growth factor.3 and 7 days after co-cultured respectively,CD133 expression of suspension cells in the 24-well plates were identified by flow cytometry,and immunofluorescence was performed for Nestin and glial fibrillary acidic protein (GFAP)expression of adherent cells.Co-culture supernatant(CCS)re-suspended 3~(rd) passage of BTSCs and cultured into 96-well plates at day 3,which were used to determine the difference in cell growth curve in both groups using a microplate reader.RESULTS AND CONCLUSION:With the cocultivation days increasing,the phenomenon that tumor sphere cells began to be decomposed,adherent and differentiated observed by an inverted microscope.BTSCs in the co-cultured group expressed GFAP and Nestin when adherent and differentiated.The higher degree of malignant brain tumor tissue used in culturing BTSCs was,the higher expression of CD133 in BTSCs was.CD 133~+ in BTSCs declined when co-cultured with WJCs.Growth curve of brain tumor stem cells cultured in CCS compared with in SFM at day 3,which indicates that the proliferation of BTSCs inhibited obviously.Results indicated that CD 133~+ expression and proliferative capacity of BTSCs went down and BTSCs underwent differentiation during the co-culture in vitro.

BACKGROUND:Bone marrow mesenchymal stem cells have low immunogenicity and immunomodulatory effect,but there are seldom reports concerning the immunomodulatory effect of Wharton's jelly-derived mesenchymal stem cells of human umbilical cord and its mechanims.OBJECTIVE:To investigate the immunomodulatory effects and mechanisms of Wharton's jelly-derived mesenchymal stem cells of human umbilical cord on varient peripheral blood T lymphocytes.METHODS:Mesenchymal stem cells were isolateded from Wharton's jelly of human umbilical cord by tissue culture.T lymphocytes from human peripheral blood were stimulated by phytohemagglutinin and co-cultured with umbilical cord Wharton's jelly-derived mesenchymal stem cells and umbilical cord Wharton's jelly-derived mesenchymal stem cells supernatant respectively to measure A value following 72 hours of coculture using multifunctional microplate reader.Expression of cytokines including transforming growth factor-beta 1(TGF-β1)and interferon-y(IFN-γ)was evaluated by enzyme-labeled immunosorbent assay.RESULTS AND CONCLUSION:Wharton's jelly-derived mesenchymal stem cells could inhibite the proliferation of T lymphocytes induced by phytohemagglutinin.The proliferation inhibition rate was 56%(P＜0.01).Wharton's jelly-derived mesenchymal stem cells supernatant also had inhibitory effects on proliferation of T lymphocytes induced by phytohemagglutinin,in a dose-dependent fashion.The proliferation inhibition rates were 8.3% and 27% respectively in the 50% Wharton's jelly-derived mesenchymal stem cells supernatant and 100% Wharton's jelly-derived mesenchymal stem cells supematant groups(P＜0.05).Wharton's jelly-derived mesenchymal stem cells significantly decreased γ-interferon secrted from T-lymphocytes(P＜0.05).The secretion of TGF-β1 was lower in the coculture of Wharton's jelly-derived mesenchymal stem cells and T lymphocytes group than Wharton's jelly-derived mesenchymal stem cells alone group(P＜0.05).These indicated that Wharton's jelly-derived mesenchymal stem cells and Wharton's jelly-derived mesenchymal stem cells supernatant have inhibitory effects on proliferation of T lymphocytes induced by phytohemagglutinin.The mechanims may be associated with cell contant and inhibition of v-interferon secrted from T-lymphocytes.

Objective:To analyze the effects of electrical acoustic stimulation (EAS) on speech and tone recognition as well as music perception in children with low-frequency residual hearing (LFRH) after cochlear implant (CI).Methods:A total of twelve Mandarin patients with LFRH who underwent unilateral CI from January 2017 to October 2020 were recruited, including 8 males and 4 females. There were 5 cases of pre-lingual deafness and 7 cases of post-lingual deafness. The median age at implantation was 12 years old (3-62 years). All patients had residual hearing (RH) before surgery, wore hearing aid (HA) timely, had an effective rehabilitation and the duration of use of electrical stimulation was 37.0±16.2 months. On the implanted side, the thresholds of 125 Hz and 250 Hz were less than and equal to 80 dB HL after implantation. A two-month follow-up clinical study was conducted with the EAS devices. The EAS effects were evaluated before, immediately after and 2 months after upgrade, including speech recognition rate, tone recognition and music tests. SPSS 23.0 software was used for statistical analysis.Results:A total of ten patients completed a two-month clinical follow-up and efficiency evaluation. Compared to the electrical stimulation, the recognition rate of spondee word significantly decreased after the immediate use of EAS (71.7±4.3 vs 79.6±3.1, P=0.018). Compared to the electrical stimulation as well as immediate use of EAS, the results of sentence in noise, tone in noise, and SRT of sentence in noise were all significantly improved at 2 months after use of EAS ( P<0.05). The pitch discrimination was significantly improved at 2 months after the use of EAS compared with that before the use of EAS ( P=0.042). Compared with before ( P=0.021) and immediately ( P=0.017) use of EAS, the ability of rhythm resolution was significantly improved. There were no significant differences in other test results ( P>0.05). Conclusions:The low-frequency acoustic information provided by EAS as well as the electrical-acoustic stimulation mode can provide rich auditory cues of speech perception in noise, tone recognition in noise, and musical discrimination for CI subjects. It can promote the improvement of complex listening ability of CI patients undergoing long-term electrical stimulation in a short time and comprehensively improve their hearing capacities.