Mechanical analysis of cortical bone trajectory screw placement in lumbar revision / 中国组织工程研究

BACKGROUND:At present,there are shortcomings and risks in the surgical revision of vertebral bodies that failed to be fixed in clinical practice.To avoid the risks of conventional revision surgery,the cortical bone trajectory technique is used to perform revision surgery on vertebral bodies that failed to be fixed.However,the mechanical properties of cortical bone trajectory technique screws in revision surgery are not clear. OBJECTIVE:The mechanical properties of cortical bone trajectory in lumbar revision surgery were analyzed by the finite element method to provide a theoretical basis for the clinical application of cortical bone trajectory in revision surgery. METHODS:CT scan data of the osteoporotic vertebral body were obtained and the L4 vertebral body model was established.The initial cortical bone trajectory placement and traditional pedicle screw in the L4 vertebral body model were completed,respectively,and their mechanical data were taken as the baseline standard for later evaluation of revision surgical performance.The traditional pedicle screw was removed and the screw path was retained.The cortical bone trajectory screw was used for secondary screw placement on the vertebral body to achieve lumbar refixation.The axial pull-out force,stability,and lumbar motion range of the revised screw were analyzed by the finite element method. RESULTS AND CONCLUSION:(1)The screw axial pull-out force of the cortical bone trajectory revision group was 25.6%higher than that of the traditional pedicle initial group.(2)In the lower,left,and right working conditions,the load-displacement ratio of screws in the cortical bone trajectory revision group increased by 18.5%,41.3%,and 35.0%,respectively,compared with the traditional pedicle initial group.The load-displacement ratio of screws in the cortical bone trajectory revision group was slightly higher than that in the traditional pedicle initial group under the above condition,but there was no statistically significant difference(P>0.05).(3)In anterior and posterior flexion conditions,lumbar motion range in the cortical bone trajectory revision group was increased by 45.5%and 36.1%compared with the traditional pedicle initial group,but there was no statistically significant difference in left bend,right bend,and axial rotation conditions(P>0.05).(4)There were no statistically significant differences in screw axial pull-out force,screw load-displacement ratio,and lumbar motion range between the cortical bone trajectory revision group and cortical bone trajectory initial group(P>0.05).(5)The mechanical data exhibited that although the revised nail track bone was damaged or lost to a certain extent,the mechanical properties of the cortical bone trajectory revision group were still better than those of the traditional pedicle initial group to a certain extent.Moreover,there was no significant difference in the mechanical properties between the cortical bone trajectory revision group and the cortical bone trajectory initial group.It provides a reference for revision surgery of lumbar internal fixation with cortical bone trajectory technique in patients with failed traditional pedicle fixation.

Design of a Novel Variable-Diameter Cortical Threaded Screw and its Application in Improving Cortical Bone Trajectory in Lumbar Spine / 医用生物力学

Objective A novel variable-diameter cortical threaded screw used in a modified cortical bone trajectory(MCBT)was designed to verify its mechanical properties using the MCBT technique.Methods According to MCBT technology,the screw pitch was fixed at 2 mm,the total length was 45 mm,the diameter of the thick rod was 5.5 mm,the diameter of the thin rod was 4.0-4.5 mm,and the length of variable-diameter position connecting the thick rod and the thin rod was 2 mm.The parameters were set based on three aspects:variable-diameter position,thread depth,and thread type.Three-factor and three-level L9 tests were conducted and screw models were established.The torsion and the bending and pull-out force of the designed screws were calculated based on the finite element method,the results were analyzed using range analysis,and then the screw models were determined.The three-dimensional(3D)model of L4 vertebral body in osteoporosis specimens was established and screws were placed according to the MCBT technique.The pull-out force of the novel variable-diameter cortical threaded screw was compared with that of a conventional non-variable-diameter cortical threaded screw.Results Range analysis showed that screw No.6(variable-diameter position:24 mm from the screw head,thread depth:0.7 mm,45° symmetrical thread)was the optimal screw.The anti-pull-out force of the No.6 variable-diameter cortical threaded screw was 13.1%higher than that of the 4.5 mm conventional non-variable-diameter cortical threaded screw,and no statistical difference in anti-pull-out force was found between the No.6 variable-diameter cortical threaded screw and the 5.5 mm conventional non-variable-diameter cortical threaded screw.Conclusions The variable-diameter position has the smallest influence on pull-out force of the screw,the thread type has the largest influence on pull-out force,and the thread depth has the largest influence on torsion and bending.Compared with that of the conventional non-variable-diameter cortical threaded screw,the variable-diameter cortical threaded screw had a smaller front end,which prevented splitting at the entrance point of the screw.The screw has a large diameter at rear end,thereby showing improved pull-out performance.The results provide a new theoretical basis for the clinical application of MCBT technology.

Dihydroartemisinin attenuates ischemia/reperfusion-induced renal tubular senescence by activating autophagy / 中国天然药物

Acute kidney injury (AKI) is an important factor for the occurrence and development of CKD. The protective effect of dihydroartemisinin on AKI and and reported mechanism have not been reported. In this study, we used two animal models including ischemia-reperfusion and UUO, as well as a high-glucose-stimulated HK-2 cell model, to evaluate the protective effect of dihydroartemisinin on premature senescence of renal tubular epithelial cells in vitro and in vivo. We demonstrated that dihydroartemisinin improved renal aging and renal injury by activating autophagy. In addition, we found that co-treatment with chloroquine, an autophagy inhibitor, abolished the anti-renal aging effect of dihydroartemisinin in vitro. These findings suggested that activation of autophagy/elimination of senescent cell might be a useful strategy to prevent AKI/UUO induced renal tubular senescence and fibrosis.

Study on the synchronization of biventricular beats with the control mode of left ventricular assist device / 生物医学工程学杂志

Right ventricular (RV) failure has become a deadly complication of left ventricular assist device (LVAD) implantation, for which desynchrony in bi-ventricular pulse resulting from a LVAD is among the important factor. This paper investigated how different control modes affect the synchronization of pulse between LV (left ventricular) and RV by numerical method. The numerical results showed that the systolic duration between LV and RV did not significantly differ at baseline (LVAD off and cannula clamped) (48.52%

Effect of Naikan cognitive therapy intervention on psychosomatic symptoms of female compulsory drug abuse addicts / 中华行为医学与脑科学杂志

Objective:To evaluate the intervention effect of Naikan cognitive therapy (NCT)on psychosomatic symptoms of female compulsory drug addicts.Methods:Seventy drug addicts who met the inclusion criteria and volunteered to participate in the study were selected and randomly divided into intervention group( n=35) and control group( n=35) with random number table method.The intervention group received 10 consecutive days of NCT, while the control group received the same period of mental health education.Before and after treatment, the two groups were assessed with symptoms check list-90(SCL-90), preceived social support scale(PSSS), simple coping style scale(SCSQ) and inclination of relapse questionnaire of drug rehabilitated addicts. Results:There was no significant difference between the two groups before the intervention (all P>0.05). Compared with pre-intervention, the total score of SCL-90((176.49±40.85) vs (152.60±31.17)), somatization, compulsion, interpersonal sensitivity, depression, anxiety, terror, paranoid and psychiatric factors were significantly decreased and the total scores of PSSS((59.09±14.60) vs (64.43±10.42)) family support, friend support and other support subscales increased significantly post-NCT intervention in the intervention group (all P<0.05). Compared with control group, the scores of positive coping((25.54±6.09) vs (22.37±7.04)) increased significantly, and the tendency of negative coping((8.20±3.59) vs (10.17±4.03)) and relapse((15.66±9.57) vs (22.11±10.18)) decreased significantly (all P<0.05) after intervention in the intervention group.There was no significant difference in the scores of all scales in the control group (all P>0.05). Conclusion:Naikan cognitive therapy can significantly improve the psychosomatic symptoms perceive social support and positive coping styles, and reduce the tendency of negative coping and relapse of female compulsory drug addicts.

The TNF-α/TNFR/NF-κB pathway in regulating alveolar macrophage apoptosis in coal workers' pneumoconiosis / 中国职业医学

OBJECTIVE: To study the mechanism of tumor necrosis factor( TNF)-α and its receptor( TNFR) signal transduction pathways in regulating cell apoptosis of alveolar macrophage( AM) in coal workers' pneumoconiosis( CWP).METHODS: Twenty-four coal workers with pneumoconiosis at stage Ⅰ were selected as CWP group and four observation subjects exposed to coal were chosen as observation group by using simple random sampling method. The bronchoalveolar lavage fluids of whole-lung lavage of two groups were collected. AMs were separated and purified. Then they were divided into 6 groups: a control group,a superoxide dismutase( SOD) group,a TNF/TNFR group,an anti-TNF-α antibody group,a Caspase-8 suppression group and a nuclear factor-κB( NF-κB) suppression group. The AMs of 6 groups with corresponding treatment were cultivated. After 24 hours,the cells were harvested and proteins extracted. The relative expression of TNF-α,TNFR1,TNFR2,Caspase-8,Caspase-3,NF-κB P50 and NF-κB P65 protein was detected by Western blotting. RESULTS: The protein relative expression of TNF-α,TNFR2,Caspase-8,Caspase-3,NF-κB P50 and NF-κB P65 in CWP group was significantly higher than those in the observation group( P < 0. 05). The protein relative expression of TNF-α,TNFR1,Caspase-8,Caspase-3 and NF-κB P50 in the TNF/TNFR group and the anti-TNF-αantibody group was lower than that of the control group( P < 0. 05). The above indexes in the anti-TNF-α antibody group were lower than that of the NF-κB suppression group( P < 0. 05). The protein relative expression of TNFR1,Caspase-8and Caspase-3 in the TNF/TNFR group was higher than that of the SOD group and the Caspase-8 suppression group( P <0. 05). The protein relative expression of TNFR1,Caspase-8 and NF-κB P50 in the TNF/TNFR group was lower than that of the NF-κB suppression group( P < 0. 05). Among the CWP patients,the relative expression of TNFR2 and NF-κB P65 in the TNF/TNFR group was lower than that of the control group( P < 0. 05),and higher than that of the SOD group( P <0. 05). CONCLUSION: AM apoptosis mediated by TNF-α/TNFR/NF-κB signal transduction pathway plays an important role in the occurrence and development of CWP. The TNF-α/TNFR/NF-κB signal transduction pathways inhibited or blocked at different stages can affect the expression of proteins related to AM apoptosis.

Influence of EMT in Radiosensitivity of PC-9:an EGFR- mutant NSCLC cell line / 实用医学杂志

Objective To explore the influence of epithelial mesenchymal transition(EMT)in radiosensi-tivity of EGFR-mutant NSCLC cell with acquired resistance to EGFR-TKI. Methods In this study,EGFR-mutant human lung adenocarcinoma cell line PC-9 and Gefitinib acquired resistance cell line PC-9/AB were used. Western blot was used to assess EMT. Wound healing migration assay was tested. CCK8,colony formation and flow cytome-try were used to evaluate survival fraction ,as the sensitivity to irradiation. Results PC-9/AB displayed radioresis-tance(P<0.05). When EMT was reversed with CDH1,its radiosensitivity was significantly higher than PC-9/AB (P < 0.05). PC-9/TGF also displayed radioresistance (P < 0.05),as well as EMT phenotype presented. Conclusion EMT enhanced the radioresistance of EGFR-mutant NSCLC cell with acquired resistance to EGFR-TKI, possibly through TGF-βpathway.

The relationships of hyperuricemia with clinical and Oxford classiifcations in children with IgA nephropathy / 临床儿科杂志

Objective To investigate the relationships of hyperuricemia with clinical and Oxford classifications in children with IgA nephropathy.Methods Clinical data of 213 children with IgA nephropathy were retrospective analyzed. According to the levels of blood uric acid, these children were divided into two groups, hyperuricemia group (n?=?51) and normal uric acid group (n?=?162). Differences of clinical index and Oxford classiifcation between the two groups were observed. Results The 24 h urinary protein, level of serum creatinine, glomerular ifltration rate (eGFR) in hyperuricemia group were signiifcantly higher than those in normal group (P all?

Synthesis and anti-inflammatory activity of p-(sulfamyl) benzylidene-linked heterocyclic ketone derivatives / 中国药科大学学报

Aim: To study the synthesis and anti-inflammatory activity of p-(sulfamyl) benzylidene-linked hetero-cyclic ketone derivatives. Methods: A series of p-(sulfamyl) benzylidene-linked heterocyclic ketone derivatives were synthesized. Anti-inflammatory activity was evaluated against xylene-induced ear oedema in mice and against carrageenan-induced paw oedema in rats. Gastrointestinal side effects in the rats were also examined after continu-ous introgastric administration of these compounds once daily for 7 days. Results: Twelve compounds( LHZ-101-LHZ-112) were synthesized and their structures were confirmed by IR, ~1H NMR, MS and elemental analysis. LHZ-105, LHZ-106 and LHZ-111 exhibited marked anti-inflammatory activity in xylene-induced mice ear swelling model. LHZ-106 and LHZ-111 showed significant anti-inflammatory activity in carrageenan-induced rat paw ede-ma model. LHZ-105, LHZ-106 and LHZ-111 had less gastrointestinal side effects than diclofenac sodium and CI-1004. Conclusion: These results suggest that some of these compounds have the potential for anti-inflammatory activity with few gastrointestinal side effects.

Analysis on Antihypertensive Use from2002to2004in50Hospitals in Guangdong Province / 中国药房

OBJECTIVE:To evaluate the situation and the tendency of antihypertensive use in guangdong province.METHODS:The sales volume,defined daily use(DDDs)and daily expense of antihypertensive from2002to2004in guangdong province were investigated and analyzed.RESULTS:The sales volume of antihypertensive from2002to2004had been in?creasing.Calcium antagonist dominated over all other antihypertensives in respect of sales volume and DDDs.CONCLUSION:Calcium antagonist dominate in the antihypertensive market in guangdong province.