1.Cloning of mutA and expression of its coding protein
Xin SHI ; Longxing NI ; Yu TIAN
Journal of Practical Stomatology 2001;0(03):-
Objective:To obtain mutA gene of Strepto c occus mutans (Ms),and to express it in E.coli DH5?.Methods: mutA gene was amplified by PCR with specific primers from genome of Ms CH43 strain. After sequencing, the gene segment was inserted into vector pProEX and expressed in E.coli DH5?.The protein expression was induced by ITPG an d the protein products were examined by 180 ml/L SDSPAGE electrophorosis. Results:The length of PCR product was 147 bp and was identical to mu tA gene reported by GenBank.The mutA gene product was expressed in E.col i DH5? with Mr of 5.7?10 3.The maximum mutA protein product amount (20% of the total bacterial protein) was obtained when the A 600 value of DH5? was 1.666,IPTG concerntration 1.0 mmol/L and induction time 6 h.Conclus ion:mutA of Ms CH43 can be cloned and expressed in E.coli DH 5?.
2.Observation of improved extra panretinal photocoagulation for high risk proliferative diabetic retinopathy
International Eye Science 2016;16(7):1322-1324
AIM: To observe the therapeutic effect and safety of improved extra panretinal photocoagulation ( E - PRP) in the treatment of high risk proliferative diabetic retinopathy (hsPDR).
METHODS: A total of 88 consecutive cases (102 eyes) with hsPDR were diagnosed by fundus fluorescein angiography(FFA) from February 2011 to December 2014 in our hospital . Fifty two eyes had been treated by improved E - PRP with 532nm frequency - doubled laser. Fifty eyes had been treated by standard PRP. All cases were checked by FFA and fundus photocoagulation every 3mo. Patients with persisting neovascularization or non perfusion area were treated with laser again. All cases were followed up 6-36mo.
RESULTS: The postoperative visual acuity had no statistical difference between two groups ( P > 0. 05). In improved E - PRP group, retinal non perfusion area and neovascularization disappeared in 35 eyes ( 67%). Effective rate was 88%. Six eyes (12%) underwent pars plana vitrectomy because of vitreous hemorrhage, fiberosis and stretched retinal detachment. In standard PRP group, retinal nonperfusion area and neovascularization disappeared in 23 eyes ( 46%). Effective rate was 66%. Seventeen eyes(34%) underwent pars plana vitrectomy because of anterior retina bleeding or vitreous hemorrhage. The rate of neovascularization disappeared and effective rate had statistical difference between two groups (P<0. 05).
CONCLUSION: It is a safe and effective methods to treat hsPDR by improved E-PRP and it was more effective than traditional PRP.
3.Study on antimicrobial resistance and the detection of staphylococcus chromosomal cassette mec typing of methicillin-resistant Staphylococcus aureus in the urban area of Jilin
Wenyan SHI ; Xianmin FENG ; Sheng YU ; Xin YU ; Honglan HUANG
Chinese Journal of Postgraduates of Medicine 2016;39(12):1080-1083
Objective To understand the molecular epidemiology characteristics and its drug resistance of methicillin-resistant Staphylococcus aureus (MRSA) in the urban area of Jilin and to provide important basis for guiding the clinical medication and prevention of the MRSA infection. Methods One hundred and three strains of MRSA from July 2013 to July 2014 in the urban area of Jilin were selected. The polymerase chain reaction (PCR) technology and multiple polymerase chain reaction were used to detect mecA gene and Staphylococcus chromosomal cassette mec typing (SCCmec) genotype of MRSA. The drug sensitivity test for 13 kinds of clinical common antibacterial drugs were detected by using the K-B method. And the source of the strains were analyzed. Results The results of SCCmec genotype of MRSA showed that SCCmecⅢtype were 62 strains, accounting for 60.2%;SCCmecⅡtype were 39 strains, accounting for 37.9%; failing to parting were 2 strains,accounting for 1.9%. Drug susceptibility test results showed that all of 103 MRSA strains were resistant to cefoxitin, cefazolin, penicillin and benzene, and drug resistance rate was 100.0%. The resistant rate to erythromycin, levofloxacin, ciprofloxacin, tetracycline, gentamicin and rifampin were 96.1%, 93.2%, 95.1%, 91.3%, 90.3%and 55.3%receptively;the resistant rate to sulfamethoxazolewas was only 1.9%;and the resistant strains to vancomycin and teicoplanin were not detected. The top three department of the distribution of the strains source were department of neurosurgery (31.1%), ICU (19.4%) and burn plastic surgery (17.5%). Conclusions The SCCmecⅢtype is the main MRSA epidemic strains, and SCCmec type II is a minor epidemic strainin the urban area of Jilin. The antibiotic resistance of MRSA is a serious problem with multiple drug resistance, but MRSA is sensitive to vancomycin and teicoplanin.
4.Changes of oxygen function of workers of long-term exposure of toluene, methanol, dimethylformamide.
Yu-feng LOU ; Xin-ping SHI ; Li-jian LOU
Chinese Journal of Industrial Hygiene and Occupational Diseases 2010;28(7):527-528
Adult
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Dimethylformamide
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adverse effects
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Glutathione
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blood
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Humans
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Male
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Methanol
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adverse effects
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Nitric Oxide
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blood
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Occupational Exposure
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Oxygen
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metabolism
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Superoxide Dismutase
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blood
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Surveys and Questionnaires
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Toluene
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adverse effects
5.Determination of Environmental Estrogens in Surface Water and Tap Water
Fu-Yu WANG ; Xin SUN ; Shi-Hua HE ; Al ET ;
Journal of Environment and Health 1992;0(04):-
Objective To understand the environmental estrogens contamination of tap water and source water. Methods Environmental estrogens in the water samples were concentrated by macroporous adsorption resin H103. The effect of environmental estrogens in concentrated samples was assessed by the recombinant yeast system. Results The results showed that some source water and tap water really contained environmental estrogens. The activity of environmental estrogens in concentrated samples of some source water increased as the volume of concentrated sample increased. The concentrate of 100 ml water sample could show the estrogenic effect. Conclusion Some source waters and tap waters in China have been contaminated by environmental estrogens. Environmental estrogens in source water can not be removed completely by drinking water treatment system of city.
6.Isolation and structural elucidation of flavones from flower of Paulownia tomentosa
Xin DU ; Yanping SHI ; Zhigang LI ; Yu LI
Chinese Traditional and Herbal Drugs 1994;0(03):-
Object To isolate and identify the flavones from the flower of Paulownia tomentosa (Thunb.) Steud., which has been used as traditonal herb medicine in the treatment of some diseases. Methods The flavones were isolated by column chromatography and their structures were elucidated through spectroscopic analysis (NMR). Results Five flavones were isolated and identified as 5, 4′-dihydroxy-7, 3′-dimenthoxyflavanone (Ⅰ), 5-hydroxy-7, 3′, 4′-trimenthoxyflavanone (Ⅱ), diplacone (Ⅲ), mimulone (Ⅳ) and apigenin (Ⅴ). Conclusion All these compounds are obtained from the flower for the first time and the flavones should be as bioactive constituents.
8.Effects of hypertriglyceridemic-waist phenotype on cognitive function in patients with type 2 diabetes
Xin GAO ; Qiukuan SHI ; Huiyan YU ; Bin QIN ; Fangkun GAO
Chinese Journal of Geriatrics 2017;36(8):840-843
Objective To investigate the effect of hypertriglyceridemic waist(HTWC)phenotype on cognitive function in patients with type 2 diabetes.Methods According to the standard of plasma triglycerides concentration≥1.7 mmoL/L,waist circumference(WC)≥ 90 cm in men or ≥80 cm in women,304 patients with type 2 diabetes were divided into four groups:normal triglycerides and waist circumference group(group A,n =65),normal waist circumference and hypertriglyceridemia group (group B,n=53),abdominal obesity and normal triglycerides group(group C,n=114),and HTWC group(group D,n =72)for prospective studies.Patients in four groups were surveyed with Mini-mental state examination (MMSE)and Montreal cognitive assessment (MOCA).And changes of cognitive function among the four groups were compared.Results Total score for the MMSE was significantly lower in group D than in group A(27.1±1.9 vs.29.0±1.3,F=2.869,P=0.019).The subscales of attention and calculation(4.0± 1.4 vs.4.6±0.9,F=1.605,P=0.047)and recall(2.2± 0.9 vs.2.6±0.6,F=1.959,P=0.043) were significantly lower in group D than in group A.Total score for the MOCA was significantly lower in group D than in group A(23.4±3.9 vs.25.9±3.6,F =1.975,P=0.031).The subscales of visuospatial and executive(3.5 ± 1.4 vs.4.1 ± 0.9,F=1.537,P =0.048),attention(5.1±1.4 vs.5.7±0.9,F=1.660,P=0.048)and orientation(5.6±1.0 vs.6.0± 0.0,F=2.362,P=0.030)were significantly lower in group D than in group A.Conclusions There is a statistically more significant decline in cognitive function in patients with HTWC phenotype and the effective intervention and treatment are needed.
9.Kinematics Modeling and Analysis of Central-driven Robot for Upper Limb Rehabilitation after Stroke.
Jinhua YI ; Hongliu YU ; Ying ZHANG ; Xin HU ; Ping SHI
Journal of Biomedical Engineering 2015;32(6):1196-1201
The present paper proposed a central-driven structure of upper limb rehabilitation robot in order to reduce the volume of the robotic arm in the structure, and also to reduce the influence of motor noise, radiation and other adverse factors on upper limb dysfunction patient. The forward and inverse kinematics equations have been obtained with using the Denavit-Hartenberg (D-H) parameter method. The motion simulation has been done to obtain the angle-time curve of each joint and the position-time curve of handle under setting rehabilitation path by using Solid Works software. Experimental results showed that the rationality with the central-driven structure design had been verified by the fact that the handle could move under setting rehabilitation path. The effectiveness of kinematics equations had been proved, and the error was less than 3° by comparing the angle-time curves obtained from calculation with those from motion simulation.
Biomechanical Phenomena
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Humans
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Models, Biological
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Robotics
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Stroke Rehabilitation
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Upper Extremity
10. Three-dimensional printed collagen/chitosan scaffold improves neurological recovery after spinal cord injury in rats
Chinese Journal of Tissue Engineering Research 2020;24(22):3474-3479
BACKGROUND: Three-dimensional (3D) printing technology can be used to prepare bioscaffolds to meet the requirements of shape, size and surface morphology of spinal cord implantation. OBJECTIVE: To investigate the effect of 3D printed collagen/chitosan scaffolds on the recovery of neurological function in rats with spinal cord injury. METHODS: The collagen/chitosan scaffolds were prepared by freeze-drying method with a mass ratio of 2:1. The 3D printed collagen/chitosan scaffolds were prepared by 3D printer. The porosity and elastic modulus of the scaffolds were measured, and the morphology of the scaffolds was observed by electron microscope. Neural stem cells were co-cultured with 3D printed collagen/chitosan scaffold, and common collagen/chitosan scaffold, respectively, for scanning electron microscope and cell counting kit-8 assay. Forty female Sprague-Dawley rats (provided by Academy of Military Sciences of PLA) were randomly divided into four groups: sham-operated, spinal cord injury, common collagen/chitosan scaffold, and 3D printed collagen/chitosan scaffold groups. The rats in the latter three groups were used to prepare complete spinal cord transected injury model, followed by filled with the corresponding scaffold materials. Basso, Beattie, Bresnahan scores of the posterior limb, slope test, neuroelectrophysiological detection and MRI were conducted at each time point after surgery. The study was approved by the Animal Ethics Committee of Tianjin Key Laboratory of Traumatic Brain Injury. RESULTS AND CONCLUSION: (1) Scanning electron microscope showed that 3D printed collagen/chitosan scaffolds had interconnected porous structure, and the internal structure of common collagen/chitosan scaffolds was disordered. (2) Neural stem cells grew well on the surface of scaffolds and fully extended. The activity of neural stem cells on the surface of 3D printed collagen/chitosan scaffolds was significantly higher than that of the common collagen/chitosan scaffold group (P < 0.05). (3) The porosity and modulus of elasticity in the 3D printed collagen/chitosan scaffold group were higher than those in the common collagen/chitosan scaffold group (P < 0.05). (4) The Basso, Beattie, Bresnahan score in the 3D printed collagen/chitosan scaffold group was higher than that in the spinal cord injury and common collagen/chitosan scaffold groups (P < 0.05) at 3-8 weeks after surgery, and the angle of slope experiment at 4, 6 and 8 weeks after surgery was higher than that in the spinal cord injury and common collagen/chitosan scaffold groups (P < 0.05). (5) The amplitude of motor evoked potential and somatosensory evoked potential in the 3D printed collagen/chitosan scaffold group were higher than those in the spinal cord injury and common collagen/chitosan scaffold groups (P < 0.05), and the latency of motor evoked potential and somatosensory evoked potential were shorter than those in the spinal cord injury and common collagen/chitosan scaffold groups (P < 0.05). (6) MRI plain scan showed that the amplitude of motor evoked potential and somatosensory evoked potential in the 3D printed collagen/chitosan scaffold group were higher than those in the spinal cord injury and common collagen/chitosan scaffold groups (P < 0.05). 3D printed collagen/chitosan scaffold group had good continuity and more nerve fiber bundles passing through the injury site. (7) The results imply that 3D printed collagen/chitosan scaffolds can promote the repair of nerve function in the spinal cord injury rats.