Simultaneous determination of zinc, cadmium, tin, lead and copper was studied in 0.2-0.3M hydrochloric acid-methanol by 1.5 grade differential anodic stripping voltammetry. A stick silver base mercurial film electrode was used as a working electrode. The peak potential of Zn, Cd, Sn, Pb and Cu was distinctly separated each other being -1.05V, -0.74V -0.55V, -0.44V and -0.25V vs SCE, respectivly, in the above solvent electrolyte.Calibration curves of Cd, Sn, Pb and Cu in range of 20 to 600 ng/ml and Zn in range of 0.2 to 4 ug/ml showed linear relation. Canned foods could be analyzed, by dilution with the supporting electrolyte after digestion of the samples with mixed acid. The juice samples could be analyzed directly without digestion, by simple 5-2000 times dilution with the supporting electrolyte. Coefficient of variation and recovey was 6.7-8.0% and 91.2-107% respectively.

Objective:To investigate the metabolic response of different load of nutrition and recombinant human growth hormone(rhGH)after major abdominal surgery. Methods:32 patients were randomly divided into three groups as fellows:Group A : low calorie load,83.68 kJ/(kg?d);Group B: low calorie load combined with rhGH,83.68 kJ/(kg?d) and rhGH 4 U/d from d1-7 after operation;Group C :high calorie load combined with rhGH,125.52 kJ/(kg?d) and rhGH 4 U/d from d1-7 after operation.The levels of serum albumin and prealbumin and the excretion of urea nitrogen in urine were measured.after operation. Results:On day 8 after operation,the level of prealbumin in group B and C were higher than in group A(P

BACKGROUND:In the initial stage of ischemia,organisms complete angiogenesis and maintain the blood supply of organization through compensatory regulation and repair,in which process a variety of cytokines,especially vascular endothelial growth factor (VEGF),have played a key role.OBJECTIVE:To observe the characteristics and rules of VEGF level changes in both ischemic tissues and blood serums at different time points after establishing rat models of lower limb ischemia.DESIGN,TIME AND SETTING:A randomized controlled animal experiment was performed at the Loboratory for Key Subjects in Dongzhimen Hospital and the Laboratory of Molecular Biology in Beijing University of Chinese Medicine from April to November in 2007.MATERIALS:A total of 42 male SD rats of 4 weeks were divided by random digits table into 6 groups,namely a control group and a model group which was subdivided into 5 groups at the time points of hour 4,day 3,weeks 1,2 and 4 post modeling respectivly.METHODS:Rat models of lower limb ischemia were established in the model group by performing ligation and mutilation operation to left femoral arteries of rats that were anesthetized with 100 g/L chloral hydrate. At the time points of hour 4,day 3,weeks 1,2 and 4 following modeling respectively,rats were selected to extract their abdominal aorta blood samples whose supernatant was then obtained through 10 minutes of 3 000r/min centrifugalization. Gastrocnemius tissues in left legs of rats were isolated at the same time. Samples in control group were obtained directly from anesthetized rats.MAIN OUTCOME MEASURES:Western blotting method was used for detecting protein expression of VEGF in ischemic tissues and ELASA method for VEGF level in serum.RESULTS:The protein expression of VEGF in ischemic tissues began to increase immediately at hour 4 following ischemia and reached a peak at day 3,after which it reduced gradually till week 2 when it reached its minimum. Then it began to increase again and reached the level close to that of normal tissues by the end of week 4 following ischemia. As for the VEGF level in serum,it decreased immediately after ischemia,with the maximum decrease amplitude between immediate and hour 4 following ischemia,a smaller one between hour 4 and week 1;From week 1 following ischemia on,it began to increase but was still lower than the normal level by the end of week 4 (P＜0.01 ).The VEGF level in serum changed with the tendency of immediate decrease from hour 4,minimum at week 1 and graduate increase after week 1 following ischemia.CONCLUSION:After ischemia in lower limb,VEGF level in ischemic tissues changes in the direction of increase-decrease-increase;VEGF level in serum changed in the direction of decrease-increase. In another words,VEGF levels after ischemia shows the characteristics of being low in serum and high in local ischemic tissues.

OBJECTIVE: To evaluate the therapeutic effect of transplantation of autologous bone marrow mononuclear cells combined with traditional Chinese medicine for the treatment of limb ischemia. METHODS: Twenty-three patients with limb ischemia were treated. G-CSF was used to stimulate the bone marrow. The mononuclear cells were separated from the aspirated bone marrow fluid in the stem cell studio. The cell amount was above 1x10(9). The transplantation was performed by the way of intra-muscular multi-injection. Traditional Chinese medicine for replenishing qi to activate blood was prescribed from the first day after operation. The pain, poikilothermia, ulcer or necrosis and ankle/brachial index (ABI) of the ischemic limb were evaluated before and after the treatment. RESULTS: The pain score and poikilothermia score decreased one month after the transplantation, with distinct differences as compared with the scores before the treatment (P<0.05). The ABI increased gradually after the treatment, and one month after the treatment, it was 0.15 higher than that before the treatment. CONCLUSION: Transplantation of autologous bone marrow mononuclear cells combined with traditional Chinese medicine can decrease the symptoms and signs of severe lower limb ischemia effectively, and improve the circulation of the ischemic area.

Exosomes are vesicles with a double globular membrane of lipids that can be secreted by a variety of cells, including stem cells. Exosomes have unique biological characteristics and irreplaceable powerful functions which play an important role in intercellular communication. The various cytokines, signal proteins, lipids and regulatory nucleic acids contained in stem cell exosomes can play a protective role against the injury of kidney, liver, heart, blood vessels and nerves. Stem cell exosomes delay the process of intervertebral disc degeneration by inhibiting the apoptosis of nucleus pulposus cells and increasing the synthesis of extracellular matrix, etc. The mechanism of its role is mainly through miRNA and related signaling pathways. Exosomes contain complex components. Although the mechanism of action of exosomes in intervertebral discs has been preliminarily explored, the components contained in exosomes are complex and the specific situation has not been fully understood, which still needs further study. In this review, the characteristics and functions of stem cell exosomes, extraction, identification and storage methods, the impacttovarious other tissues, as well as the effects on intervertebral discs and their mechanisms were elaborated in order to provide a basis for the study of intervertebral disc degenerative diseases.

Objective:To investigate the effects of exosomes of human nucleus pulposus cells (NPCs) on the differentiation of urine derived stem cells (USCs) into nucleus pulposus-like cells.Methods:USCs and NPCs were isolated and cultured in vitro. The exosomes of NPCs were extracted and detected by Western-blot. USCs cytoplasm was transfected with GFP lentivirus, while nucleus was transfected with DAPI dye. The NPCs exosomes were transfected with PKH26 dye. After co-incubation for 12 h, USCs and NPCs exosomes were observed by macroscopy. USCs differentiation was induced by NPCs exosomes and non-contact co-culture methods. The relative expression of marker gene mRNA of nucleus pulposus cells in each group and the absorbance at 450 nm wavelength were detected.Results:The isolated USCs had the ability to differentiate into osteocytes, adipocytes and chondrocytes with high expression of marker CD29 (99.57%), CD44 (97.46%) and CD73 (97.71%) and with low expression of negative proteins CD31 (0.59%) and CD45 (0.19%). The isolated NPCs highly expressed nuclear pulposus cell marker COL2A1, ACAN and SOX-9. The exosomes extracted from NPCs showed high expression of exosome marker CD63, CD81 and Tsg101. After 12 h co-incubation, NPCs exosomes fused with USCs membrane and appeared in the cytoplasm of USCs. At 3, 5 and 7 days of co-culture, the absorbance value of USCs cells in exosome group (0.44±0.004, 0.76±0.004, 0.82±0.006) was higher than that in co-culture group (0.39±0.022, 0.63±0.035, 0.69±0.012) ( P<0.05). The mRNA relative expression of USCs nucleus pulposus marker genes ACAN (1.80±0.31, 3.50±0.21, 5.35±0.31, 7.46±0.12), COL2A1 (1.43±0.15, 4.33±0.23, 6.89±0.22, 8.11±0.31), SOX-9 (2.21±0.13, 3.13±0.11, 3.96± 0.14, 4.52±0.26) and HIF-1α (1.45±0.16, 2.14±0.21, 4.31±0.41, 4.01±0.25) in exosomes group were significantly higher than those in the control group ( P<0.05) at the 3rd, 7th, 14th and 21st days. The mRNA relative expression of USCs nucleus pulposus marker genes ACAN (5.69±0.21, 6.69±0.13), COL2A1 (6.33±0.17, 7.89±0.15), SOX-9 (4.19±0.29, 4.38±0.12), HIF-1α (4.49±0.32, 4.96±0.26) in exosomes group were significantly higher than those ACAN (3.69±0.35, 5.13±0.23), COL2A1 (3.40±0.16, 6.79±0.19), SOX-9 (2.26±0.32, 3.69±0.26), HIF-1α (2.39±0.11, 3.96±0.13) in non-contact co-culture group ( P<0.05) at the 14th and 21st days. Conclusion:Human nucleus pulposus exosomes could induce differentiation of human USCs into nucleus pulposus-like cells in vitro. Compared with non-contact co-culture, exosomes have higher induction efficiency and can better maintain the proliferation activity of nucleus pulposus-like cells

Objective:To evaluate the volume changes of cervical longus and cervical extensor after anterior cervical discectomy and fusion (ACDF), and the correlation with the clinical efficacy of patients.Methods:All of 57 patients with cervical spondylotic myelopathy who underwent single-segment ACDF surgery from January 2013 to December 2018 were analyzed. The follow-up time was 23.0±4.8 months (range 16-34 months). All included subjects underwent MR examination within 1 week before operation and 3rd, 12th months after operation and at the last follow-up. The axial section cross section area (AxCSA) of the cervical longus and the ratio of length to short diameter line (RLS) at the level of each disc of C 2-C 7 were measured on the axial T2WI. Calculate the volume of the cervical longus based on the layer thickness. At the same time, measure the cervical extensor cross-sectional area (CESA) of the same level including the multifidus, cervical semispinous muscle, semispinous head, splinter head, and cervical splinter muscles, and compare CESA with the corresponding vertebral cross-sectional area (VBA). The ratio is analyzed as the volume of the neck extensor muscle, namely CESA/VBA. At the 3rd and 12th months after operation and at the last follow-up, the axial pain was assessed by visual analogue scale (VAS) for assessing pain, and the modified Japanese Orthopedic Association score (mJOA) and the neck dysfunction index (NDI) were used to assess the functional status of the cervical spine. Analyze the morphological changes of thecervical longus and extensor cervical muscles before and after the operation and during the follow-up period, and analyze the correlation with VAS, mJOA, and NDI. Results:Compared with the preoperative period, the average AxCSA of the surgical segment decreased at the 3rd and 12th months after the operation and at the last follow-up. The difference was statistically significant ( F=24.113, P<0.05), which was changed from 140.84±19.51 mm 2 respectively reduce to 117.74±17.15 mm 2 ( t=6.714, P<0.05), 116.37±18.67 mm 2 ( t=6.841, P<0.05) and 116.27±18.65 mm 2 ( t=6.873, P<0.05). Compared with preoperatively, they were reduced by 16.40%, 17.37% and 17.45%, respectively, while the average RLS of surgical segments increased slightly, and the difference was statistically significant ( F=22.612, P<0.05), which increased from preoperative 1.97±0.67 to 2.73±0.60 (38.58% increased, t=6.380, P<0.05), 2.82±0.64 (43.15% increased, t=6.926, P<0.05) and 2.74±0.62 (39.09% increased, t=6.368, P<0.05). The volume of thecervical longus of the patients decreased after the operation, and the difference was statistically significant ( F=64.511, P<0.05), which decreased from 8853.48±458.65 mm 3 before the operation to 7834.53±461.59 mm 3 (11.51% decreased, t=11.822, P<0.05), 7926.42±456.24 mm 3 (10.47% decreased, t=10.819, P<0.05), 7892.38±450.78 mm 3 (10.86% decreased, t=11.283, P<0.05). There were no statistically significant differences in the non-surgical segment AxCSA, RLS and the volume of thecervical longus at the 3rd and 12th months after surgery and the last follow-up ( P>0.05). There was no statistically significant difference of CESA and CESA/VBA compared to preoperative in the surgical segment and non-surgical segment ( P>0.05). Pearson correlation analysis showed that the volume of cervical longus and VAS at the 3rd month ( r=-0.308, P<0.05), the 12th month ( r=-0.210, P<0.05) and the last follow-up ( r=-0.404, P<0.05) were negatively correlated; Among the volume of cervical longus and NDI in the 3rd month ( r=-0.511, P<0.05), 12th month ( r=-0.518, P<0.05) and the last follow-up ( r=-0.352, P<0.05), there was a negative correlation; However, there was no statistically significant correlation between the cervical longus muscle volume and mJOA at each follow-up time point ( P>0.05); There was no significant correlation between CESA/VBA and VAS, NDI, and mJOA at the 3rd, 12th and last follow-up ( P>0.05). Conclusion:The volume and morphology of cervical longus after ACDF was significantly reduced compared with that before the operation, but the volume and morphology of the cervical extensor muscle did not change significantly. ACDF surgery mainly affects the cervical longus corresponding to the surgical segment, and the volume is negatively correlated with the VAS and NDI during follow-up.

Objective To explore the management strategy and indications for revisionary internal fixation after percutaneous kyphoplasty/percutaneous vertebroplasty (PKP/PVP) in cancellous vertebral fractures.Methods A retrospective analysis was made of the 676 cases of single-segment PKP/PVP at Department of Orthopaedics,The Affiliated Hospital to Qingdao University from January 2008 to January 2019.They were subjected to 4 different managements after their primary PKP/PVP:rehabilitation without any treatment in 637 cases,conservative treatment in 19 cases (including 3 ones who refused any revision),KP/VP revision in 12 cases and internal fixation revision in 8 cases.The rate of volume reduction after bone cement dispersion (Vx) was calculated using software Mimics 17.0 on the basis of primary CT data of all the patients.The correlation regression analysis was made between the revision rate and the approximate quantization value of Vx.The Glasgow Coma Score (GCS) of conscious state was used to evaluate the 39 patients after failure of their primary surgery before the surgical strategy for revision was worked out.The cobb angle,pelvic incidence angle (PI),pelvic inclination angle (PT),sacral inclination angle (SS),sagittal deviation (SVA),pain visual analogue scale (VAS) were measured and recorded before operation and at the last follow-up for the KP/VP revision group and internal fixation revision group,indicated as △cobb,△PI,△PT,△SS,△SVA and △VAS,respectively.The indexes were compared between the 2 groups.Results The incidence of osteoporotic vertebral fractures treated with internal fixation revision was 1.18％ (8/676).The correlation between Vx and revision rate was y =0.53 + 0.04x (P ＜ 0.05).The regression analysis showed that Vx was positively correlated with the revision rate (r2 =0.860,P =0.001) and the fitting curve was correlated (r2 =0.916,P =0.001).The GSC scores revealed 31 normal,6 mild disturbance and 2 moderate disturbance cases.There were no significant differences in gender,age or VAS scores between the KP/VP revision group and the internal fixation revision group (P ＞ 0.05).There was a significant difference in △cobb between the 2 revision groups (6.3° ± 7.5° versus 19.2° ± 14.8°) (P ＜0.05),but there were no significant differences between the 2 groups in △PI (4.1°±5.2° versus 3.3°±6.7°),△PT (0.7°±4.6° versus 0.4° ± 3.2°),△SS (3.7° ± 6.2° versus 3.1° ± 5.3°) or △SVA (-3.2 ± 11.9 mm versus-7.9 ± 9.5 mm) (P ＞ 0.05).Conclusions The outcomes of primary PKP/PVP have a great impact on the decision-making of internal fixation revision.The mode and extent of diffusion after initial vertebral cement perfusion are particularly related to the revision rate.The revision plan should depend on clinical symptoms.The internal fixation revision should be individualized to ensure the quality of life of the patients in line with the principles of "resolving symptoms" and "moderate correction".

Objective:To compare the effect of robot navigation system (Tian Ji robot system) plus 3D printing and traditional C-arm X-ray fluoroscopy in assisting percutaneous kyphoplasty (PKP) or percutaneous vertebroplasty (PVP) for treatment of Kümmell disease.Methods:A retrospective case-control study was conducted to analyze the clinical data of 40 patients with Kümmell disease treated at Honghui Hospital Affiliated to Xi'an Jiaotong University School of Medicine from December 2017 to February 2019, including 12 males and 28 females, with an average age of 56.4 years (range, 42-71 years). In observation group, 20 patients underwent PKP or PVP assisted by the robot navigation system and 3D printing. In control group, 20 patients underwent PKP or PVP assisted by the traditional C-arm X-ray fluoroscopy. The operation time and incidence of complications were observed. The visual analogue scale (VAS), Oswestry disability index (ODI), Cobb angle and anterior vertebral height were compared before operation, 1 day and 3 months after operation.Results:All patients were followed up for 3.5-8.6 months (mean, 6.7 months). The operation time in control group was (32.2±5.8)minutes, compared with (26.7±3.6)minutes in observation group ( P<0.05). The incidence of cement leakage was 0% (0/20) in the observation group and 5% (1/20) in control group ( P>0.05). One day after operation, in observation group and control group, the VAS was (2.1±0.3)points and (3.7±0.8)points, the ODI was 14.3±1.8 and 25.5±5.7, the Cobb angle was (20.6±1.2)° and (22.4±0.6)°, and the anterior height of vertebral body was (21.2±0.8)mm and (17.6±0.7)mm, respectively, showing significant improvement compared with those before operation ( P<0.01). Three months after operation, in observation group and control group, the VAS was (1.8±0.4)points and (2.8±0.8)points, the ODI was 12.3±1.5 and 21.6±2.3, the Cobb angle was (18.1±0.8) ° and (20.5±1.6)°, and the anterior height of vertebral body was (20.1±1.8)mm and (16.8±1.3)mm, showing no significant difference compared with those at day 1 after operation ( P>0.05). There were significant differences in the VAS, ODI, Cobb angle and anterior vertebral height between the two groups 1 day and 3 months after operation ( P<0.01). Conclusion:For Kümmell disease, with assistance with the robot navigation system combined with 3D printing, PKP or PVP can more effectively reduce the pain of patients, improve the quality of life, restore the anterior height of vertebral body, and realize the individualized treatment in comparison with the traditional C-arm X-ray fluoroscopy.

According to the pathological characteristics of symptomatic chronic thoracic and lumbar osteoporotic vertebral fracture (SCOVF), the different clinical treatment methods are selected, including vertebral augmentation, anterior-posterior fixation and fusion, posterior decompression fixation and fusion, and posterior correction osteotomy. However, there is still a lack of a unified understanding on how to choose appropriate treatment method for SCOVF. In order to reflect the new treatment concept and the evidence-based medicine progress of SCOVF in a timely manner and standardize its treatment, the clinical guideline for surgical treatment of SCOVF is formulated in compliance with the principle of scientificity, practicability and advancement and based on the level of evidence-based medicine.