BACKGROUND:Studies have demonstrated that tetrandrine has protection on acute spinal cord injury,but the specific mechanism remains poorly understood.OBJECTIVE:To study the protection of tetrandrine on rat acute spinal cord injury and to study its mechanism from apoptosis pathway.METHODS:A total of 100 rats were randomly divided into 4 groups.All rats were prepared for spinal cord injury models using modified Allen method except that in the sham-surgery group.Methylprednisolone and tetrandrine was injected into rats in the methylprednisolone and tetrandrine groups by tail intravenous injection prior to and at 24,48 hours after model preparation.The same volume of physiological saline was injected in the sham-surgery and model groups.Basso-BeatUe-Bresnahan(BBB score)was recorded at 8 hours,1,3,7 and 14 days after model preparation.The morphological changes of spinal cord injury sites were observed by hematoxylin-eosin staining and the expressions of bcl-2 and bax were determined by immunohistochemistry.RESULTS AND CONCLUSION:The BBB score of methylpradnisolone and tetrandrine groups were significantly higher than that model group at 7 and 14 days(P<0.05),but there were no significant difference between the methylprednisolone group and tetrandrine group(P>0.05).Hematoxylin-eosin staining showed that the spinal cord injured severely at 3-7 days,the injury degree in the methylpradnisolone group and tetrandrine group was slighter than that of the model group,with smaller bax expression and greater bcl-2 expression(P<0.01).The findings demonstrated that,tetrandrine is able to protect neurons from apoptosis and promote the nerve function recovery by inhibiting the expression of Bax and promoting the expression of Bcl-2.Its effect is not inferior to methylprednisolone.

BACKGROUND: There are few reports about vascularization in the repairing of bone defect by heterogeneous deproteinized bone.OBJECTIVE: To verify the vascularization characteristics of heterogeneous deproteinized bone, tissue engineering scaffold material, in the repairing of large segmental bone defect.DESIGN, TIME AND SETTING: The randomized controlled animal experiment was performed between March 2005 and February 2007 at the Third Military Medical University, Chongqing, China.MATERIALS: Twenty-four 10 to 12 months old goats, weighing (22.5±2.5)kg, were obtained from the Animal Center of the Third Military Medical University, Chongqing, China. Segmental bone defects of 20 percent right tibia middle and inferior diaphysis of the 24 goats were made.METHODS: The 24 goats were divided into test group (n=16) and control group (n=8) randomly. Goats in test group were implanted with deproteinized bone+autologous MSCs+recombinant human bone morphogenetic protein-2 (rhBMP-2), goats in control group were implanted with autograft bone, and all fixed with half-ring sulcated external fixator. Every 4 weeks, 3 goats were killed after ink perfusing through femoral artery. A thick slice of new bone tissue was made to observe the vascularization.MAIN OUTCOME MEASURES: Vascularization of new bone observed through gross anatomy and imaging; vascular network of new bone observed through thick section, blood vessel amount and area measured by Image-proplus really image analysis software.RESULTS: No goat was infected or dead. Animal soft tissue was dyed black, blood vessels'size, ditribution and network structure were observed in subcutaneous tissue, fascia and periosteum. At 4 weeks postoperation implant margin became crude in the defect area; at 8 weeks postoperation transparent bone absorbing area of different size and irregular shape appeared; after 12 weeks postoperation high-dense calcification shadow appeared at the ends of defect bone and new bone connected with the ends completely. On 4 to 24 weeks postoperation, the blood vessel amount became large, alignment became regular, and their size and distribution became uniform. It showed no significant difference in blood vessel amount and area between 2 groups (P>0.05).CONCLUSION: Composite of heterogeneous deproteinized bone+autologous MSCs+rhBMP-2 has the same vascularization degree. of autogeneous bone graft in repairing of large segmental tibia defect.

As an important part of the enteric nervous system(ENS),enteric glial cells(EGCs)play an important role in regulating intestinal homeostasis and maintaining intestinal health in hu-mans and animals.This review focuses on the role of EGCs in maintaining intestinal barrier homeo-stasis,maintaining gastrointestinal transit and motor function,regulating the niche of intestinal cells,and the role in the occurrence and development of intestinal diseases,hoping to provide new ideas for further research on the function and mechanism of EGCs in the intestine and the occur-rence,development and treatment of related intestinal diseases.

Objective To discuss the application of mobile C-arm CT scan in the operations for thoracolumbar burst fractures of type A3.Methods From January 2012 to December 2014,21 patients with single-segment thoracolumbar burst fracture (AO type A3) were treated.They were 15 males and 6 females,aged from 17 to 68 years (average,43.6 years).By the American Spinal Injury Association (ASIA) grading,one was grade A,2 were grade B,12 grade C,4 grade D and 2 grade E.Preoperative CT examination was conducted.Mobile C-arm CT scan was performed to evaluate reduction of the fragments after the fracture was reset by posterior pedicle screwing.Laminotomy for canal decompression or reduction of the fragments would be performed if it was indicated by the results of mobile C-arm CT scan.CT examination was conducted postoperatively to assess the fracture reduction and recovery of the canal calibre.Results All the patients were followed up for an average of 15.5 months (from 10 to 18 months).Their cobb angle,vertebral anterior margin compression rate,spinal occupancy rate,vertebral translocation rate and visual analogue score at postoperation and final follow-up were significantly improved compared with their preoperative values (P ＜ 0.05),but there were no significant differences between postoperation and final follow-up in all the above indexes (P ＞ 0.05).Postoperative ASIA grading showed that the spinal function was improved from grade B to grade C in one,from grade C to grade D in 4 cases,from grade C to grade E in 5 cases,and from grade D to grade E in 3 cases.Conclusion Since intraoperative C-arm CT scan can help decide whether laminectomy for canal decompression is conducted or not in the surgery of thoracolumbar burst fractures,it enhances the surgical safety and reliability.

Background Bacteria are the most diverse and widely sourced microorganisms in the indoor air of subway stations, where pathogenic bacteria can spread through the air, leading to increased health risks. Objective To understand the status and distribution characteristics of indoor air bacterial pollution in subway stations and compartments in a city of Central South China, and to provide a scientific basis for formulating intervention measures to address indoor air bacteria pollution in subways. Methods Three subway stations and the compartments of trains parking there in a city in Central South China were selected according to passenger flow for synchronous air sampling and monitoring. Temperature, humidity, wind speed, carbon dioxide (CO₂), fine particulate matter (PM_2.5), and inhalable particulate matter (PM₁₀) were measured by direct reading method. In accordance with the requirements of Examination methods for public places-Part 3: Airborne microorganisms (GB/T 18204.3-2013), air samples were collected at a flow rate of 28.3 L·min⁻¹, and total bacterial count was estimated. Bacterial microbial species were identified with a mass spectrometer and pathogenic bacteria were distinguished from non-pathogenic bacteria according to the Catalogue of pathogenic microorganisms transmitted to human beings issued by National Health Commission. Kruskal-Wallis H test was used to compare the subway hygiene indicators in different regions and time periods, and Bonferroni test was used for pairwise comparison. Spearman correlation test was used to evaluate the correlation between CO₂ concentration and total bacterial count. Results The pass rates were 100.0% for airborne total bacteria count, PM_2.5, and PM₁₀ in the subway stations and train compartments, 94.4% for temperature and wind speed, 98.6% for CO₂, but 0% for humidity. The overall median (P₂₅, P₇₅) total bacteria count was 177 (138,262) CFU·m⁻³. Specifically, the total bacteria count was higher in station halls than in platforms, and higher during morning peak hours than during evening peak hours (P<0.05). A total of 874 strains and 82 species were identified by automatic microbial mass spectrometry. The results of identification were all over 9 points, and the predominant bacteria in the air were Micrococcus luteus (52.2%) and Staphylococcus hominis (9.8%). Three pathogens, Acinetobacter baumannii (0.3%), Corynebacterium striatum (0.1%), and Staphylococcus epidermidis bacilli (2.2%) were detected in 23 samples (2.6%), and the associated locations were mainly distributed in train compartments during evening rush hours. Conclusion The total bacteria count in indoor air varies by monitoring sites of subway stations and time periods, and there is a risk of opportunistic bacterial infection. Attention should be paid to cleaning and disinfection during peak passenger flow hours in all areas.