BACKGROUND:BioFlex system as a new pedicle screw fixation of dynamic stabilization device has less been reported concerning its biomechanics.
OBJECTIVE:To study the effect of BioFlex system fixation at different decompression ranges on disc stress at adjacent segments.
METHODS:Eight samples of fresh calf spines were used. Under physiologic axial loads (500, 900, 2 300 N), electronic universal testing machine was used to simulate the lumbar spine at three physiological states (standing, sitting and bending, standing on a portable 20 kg weight and bending). Progressive decompression modeling for each specimen and dividing into five groups:(1) complete status group;(2) complete status+BioFlex group;(3) partial laminectomy+BioFlex group;(4) 1/2 medial facetectomy+BioFlex group;(5) total facetectomy+BioFlex group. Strain gauges were used to record the stress of disc annulus. Electronic universal testing machine was used to record load-displacement curve and calculate stiffness.
RESULTS AND CONCLUSION:(1) The stress of the adjacent segment of the intervertebral disc increased with the expansion of the range of decompression. Compared with the complete status, stress obviously increased after BioFlex fixation, showing significant differences (P<0.05). The stress was significantly increased in the 1/2 medial facetectomy+BioFlex group compared with the partial laminectomy+BioFlex group (P<0.05). However, no significant difference was detected between the partial laminectomy+BioFlex group and complete status+BioFlex group, and between total facetectomy+BioFlex group and 1/2 medial facetectomy+BioFlex group (P>0.05). (2) Axial stiffness reduced with the expansion of the range of decompression. Compared with the complete status, axial stiffness noticeably increased after BioFlex fixation. The difference was not significant among four kinds of reconstruction structures. (3) These findings confirmed that after BioFlex fixation, with the expansion of the range of decompression, the stress of adjacent segments of intervertebral disc gradual y increased, but different ranges of decompression cannot affect the stiffness of reconstruction structure.

Objective To evaluate the effect of endoscopic variceal ligation(EVL) combined with splenectomy for the patients with portal hypertension. Methods Thirty two cases of portal hypertension underwent EVL plus splenectomy from May 1999 to May 2002 in our department. The patients were registered and followed up in the third, sixth and twelfth months after operation respectively. Re ligations were performed in case of relapsed varices. Results Thirty one patients were followed up for ≥2 years.Of them,esophageal varices recrrented in 6.4% of patients during following-up period,but no reblecding, and no death caused by hepatic encehpalopathy or other complications.Conclusions EVL combined with splenectomy has less trauma , less postoperative complications and high eradication rate of esophageal varices, so it can be used safely in the treatment of patients with ruptured esophageal varices.

Objective To Study the effect of splenectomy plus endoscopic varices ligation (SEVL) in the treatment of portal hypertension. Methods SEVL was carried out in 38 patients with portal hypertension from January 2000 to June 2002. The authors compared hemodynamic parameters and gastric emptying time before and after the operation. The incidence of upper gastrointestinal bleeding, the disappearance rate of esophageal varicosis, the outcomes of portal hypertensive gastropathy (PHG) and the incidence of complications were recorded at postoperative 3 weeks, 6 months, 12 and 18 months, respectively. Results Postoperatively, the free portal pressure, portal flow volume and velocity were significantly reduced in all the cases ( P 0.05). Portal thrombosis was seen in 6 cases (6/38, 15.8%). Conclusions SEVL has little influence on gastric emptying and PHG, offering a high disappearance rate of varicosis and a low incidence of complications.

Objective To understand the health of the electronic waste (e-waste) treatment workers and the adverse effects of e-waste on the workers engaged in e-waste dismantlement.Methods Health states were assessed by questionnaire investigation on 226 e-waste dismantlement workers and 172 non e-waste dismantlement workers (control group).Results The prevalence rates of headache/vertigo(47.7%),tetter /itch (15.0%),nausea(11.1%),insomnia(9.7%),hypomnesia (5.3%),nasal obstruction(5.3%),and conjunctiva congestion(4.8%) in e-waste dismantlement workers were significantly higher than that in the control group,and it seemed that the severity of the symptoms was strongly related to the type of work.Furthermore,there was a tendency that rate of insomnia raised with the length of service in the circuit boards dismantlement group.Conclusion E-waste dismantlement will produce adverse effects on health of the employed workers.

Action Potentials ; drug effects ; Animals ; CA1 Region, Hippocampal ; cytology ; Drug Antagonism ; Male ; Neurons ; drug effects ; Pentylenetetrazole ; pharmacology ; Propofol ; pharmacology ; Rats ; Rats, Wistar ; Synaptic Transmission ; drug effects

China ; Inventions

Objective To explore the clinical effect of posterior indirect reduction and internal fixation and laminectomy in the treatment of thoracolumbar vertebrae burst fracture complicated with spinal cord injury.Methods Eighty patients with thoracolumbar vertebrae burst fracture and spinal cord injury treated in our hospital from March 2014 to March 2015 were selected as the objects,and they were divided into reset group and laminectomy group with forty cases in each group according to surgical method.All the patients were followed up for 1 year,the lumbar function of two groups at 1 week and 1 year after operation were observed respectively,and the pain degree was observed in 1month,3 months and 6 months after operation.The amount of bleeding,operation time,hospitalization time and fracture healing time were observed.Neurological function was assessed by classification criteria of the American Spinal Cord Injury Association(ASIA),and incidence of complications was figured in the two groups.Results The anterior heights of the injured vertebra were higher than those before the operation,and the Cobb's angles were lower than those before the operation,the differences were significant(P ＜ 0.05);while there was no significant differences in the anterior heights of the injured vertebra between the two groups at 1 week and 1 year after operation(P ＞ 0.05).VAS scores of the two groups after 1 month,3 months and 6 months decreased significantly when compared with the preoperative scores(P ＜ 0.05),and VAS scores of each time in the reset group were significantly lower than those in the laminectomy group(P ＜ 0.05).The amount of bleeding,operation time,hospitalization time and fracture healing time in the reset group were less than those in the laminectomy group (P ＜ 0.05).The neurological function recovery of the two groups were significantly improved when compared with that before the operation(P ＜0.05).There was no significant difference in recovery of neurological function between the two groups(P ＞ 0.05).The complication rate was 7.50％ in the reset group,lower than 12.50％ of the laminectomy group,the difference was significant (P ＜ 0.05).Conclusion Posterior indirect reduction and internal fixation of lamina both have a certain effect in the treatment of thoracolumbar vertebrae burst fracture complicated with spinal cord injury.But posterior indirect reduction has less complications and less amount of bleeding,which is beneficial to postoperative recovery.

BACKGROUND:Human umbilical cord blood-derived mesenchymal stem cels can be induced through the co-culture to differentiate into other cels, but how to get more seed cels for tissue engineering is one of the most difficult problems. OBJECTIVE: To investigate the role of the different concentrations of thyroxine in chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cels by co-culture with rabbit chondrocytes. METHODS:Human umbilical cord blood-derived mesenchymal stem cels were co-cultured with rabbit chondrocytes at 2:1, and stimulated by medium containing different concentrations of thyroxine (0, 0.01, 0.1 and 1, 10 μmol/L). Co-cultured cels with no thyroxine served as control group. After 14 days of co-culture, the cel RNA and protein were extracted, mRNA expressions of aggrecan and colagen type II were detected by real-time PCR, and protein expression of aggrecan and colagen type II were detected by western blot assay. RESULTS AND CONCLUSION:After intervention with 0.01, 0.1, 1, 10 μmol/L thyroxine, the mRNA and protein expressions of aggrecan and colagen type II were enhanced with the increase of thyroxine concentration, which were significantly different from those in the control group (P < 0.05). Experimental findings indicate that high levels of thyroxine can enhance the chondrogenic ability of human umbilical cord blood-derived mesenchymal stem cels co-cultured with rabbit chondrocytes.

Objective To study the effectiveness of comprehensive control measures based on systematic ecological system construction to interrupt the transmission of schistosomiasis in hilly endemic regions in Sichuan Province ,so as to provide the ev?idence for adjustment of schistosomiasis prevention and control strategies. Methods A high endemic area of schistosomiasis, Panao Township of Dongpo District in Meishan City,was selected as a demonstration area. The comprehensive measures for schistosomiasis control with focus on systematic ecological management were implemented,and the income of residents,index?es of schistosomiasis control effect and so on were investigated before and after the intervention and the results were compared. Results The project based on systematic ecological system construction started in 2009 and 317.351 million Yuan was put into the construction. The construction included economic forest plant base(1 866.68 hm2,72.66%of the total farmland areas),eco?logical protection gardens(585.35 hm2)and so on. Totally 97.04% of historical areas with Oncomelania hupensis snails were comprehensively improved. In 2015,the peasants' pure income per capita increased 4 938 Yuan,with the average annual growth rate of 14.69%. All the farm cattle were replaced by the machine. The benefit rate of water improvement was increased by 52.84%and the coverage rate of harmless toilets increased by 18.30%. The positive rate of serological tests for schistosomiasis decreased from 7.69%to 3.50%,and the positive rate of parasitological tests decreased from 1.18%to 0. The area with snails was decreased from 23.33 hm2 to 0. The awareness rate of schistosomiasis control knowledge and correct behavior rate of the resi? dents increased from 85.50%and 82.60%to 95.70%and 93.90%respectively. Conclusions The comprehensive schistosomia?sis control measures based on systematic ecological management are conform to the currently actual schistosomiasis prevention and control work in hilly endemic regions,and have good ecological economic benefit and schistosomiasis control effectiveness, which provide an effectively new model of prevention and control for advancing process,consolidating the effect,finally realiz?ing goal of interruption and elimination of schistosomiasis in hilly endemic regions.

Objective To explore the mechanism of insulin resistance regulated by fibroblast growth factor 21 (FGF21)and identify its role in oxidative stress.Methods High-fat diet-induced obese mice were treated with FGF21 ,and hepatic oxidative stress markers such as iNOS and insulin signaling molecules such as IRS-1 and Akt were assessed by Western blot and co-immunoprecipitation.Meanwhile,liver steatosis was assessed in liver sections stained with oil red O.Results Obese mice in FGF21 group showed reduced body weight,blood glucose and serum insulin levels,and improved insulin sensitivity as measured by glucose tolerance testing (GTT)and insulin tolerance testing (ITT)compared with obese mice in vehicle group.Meanwhile,FGF21 treatment in obese mice decreased protein expressions of iNOS and TNF-α,and increased insulin-stimulated IRS-1 tyrosine phosphorylation and Akt Ser-473 phosphorylation,indicating that FGF21 inhibited hepatic oxidative stress and restored impaired insulin signaling.Additionally,we found significantly reduced lipid accumulation in liver sections stained with oil red O in FGF21-treated obese mice.Conclusion Our results support the notion that FGF21 is an important regulator of insulin resistance and that FGF21 may reduce lipid accumulation in the liver,restore hepatic insulin signaling and improve insulin sensitivity in obese mice,at least in part,by inhibiting hepatic oxidative stress.Therefore,FGF21 has a potential value in clinical application.