BACKGROUND:Many scholars have developed a variety of dynamic elastic spine fixator. After biomechanical research, animal experiments and clinical application found that no one elastic spine fixator was general y recognized clinical y. OBJECTIVE:To compare the stress difference between“X”-shaped spine dynamic fixation and traditional pedicle screw fixation. METHODS:Three-dimensional finite element models of“X”-shaped spine dynamic fixation and traditional pedicle screw fixation were established according to adult spine imaging data. Mechanical differences in vertical compression, flexion, extension, lateral bending and rotation were compared between the two groups. RESULTS AND CONCLUSION:The stress at vertical compression was lower than that at flexion, extension, lateral bending and rotation in both groups. The stress at“X”-shaped spine dynamic fixation mainly focused on“X”-shaped connecting rod, but the stress of traditional pedicle screw fixation mainly focused on conjunction of screw-rod. Moreover, the stress of the screw of“X”-shaped spine dynamic fixation was significantly less than that of traditional pedicle screw fixation (P<0.001). These results suggest that“X”-shaped spine dynamic fixation system can share stress of screws and reduce the postoperative stress concentration compared with traditional pedicle screw fixation.

Objective To construct an RNAi lentiviral vector targeting rat CD86 gene and detect its effect of gene silencing in dendritic cells. Methods The effective sequence of siRNA targeting rat CD86 gene was confirmed in our previous work. DNA oligo containing short hairpin frame was synthesized and re-annealed, and then cloned into pGCL-GFP lentivind expression vector. PCR and sequencing analysis were made for verifying the positive clones. The virus packaging plasmids were transfected into 293T cells to har-vest shRNA lentivirus. After infection in dendritic cells, real-time PCR and Western blot were performed to determine the expression level of CD86 at mRNA and protein of NC( negative control virus). Results PCR and sequencing analysis revealed that shRNA plasmid was correctly constructed. Virus with a titer of 2×108 TU/ml was successfully packaged. CD86 expression in dendritic cells can be knockdown at both mRNA and protein level by virus infection as characterized by 90.6% decrease of mRNA and significant inhibition of protein compared with NC. Conclusion The recombinant lentiviral shRNA expressing vector targeting rat CD86 gene has been successfully constructed and packaged. CD86 mRNA and protein can be effectively down-regulated in dendritic cells.

Objective:To construct a RNAi lentiviral vector targeting rat CD80 gene and detect its effect of gene silencing in NRK and IEC6 cells.Methods:The effective sequence of siRNA targeting rat CD80 gene was confirmed in our previous work.Oligo-DNA fragment containing short hairpin frame was synthesized and reannealed,and then cloned into pGCSIL-GFP lentiviral expression vector.PCR and sequencing analysis were made for verifying the positive clones.The virus packaging plasmids were transfected into 293T cells to harvest shRNA lentivirus.After infection in NRK and IEC6 cells,Real-time PCR was performed to determine the expressing level of CD80.Results:PCR and sequencing revealed that shRNA plasmids was correctly constructed.Virus with a titer of 4×10~8 TU/ml was successfully packaged.CD80 expression in NRK and IEC6 cells could be knockdown by virus infection as characterized by 66.9% and 63.5% decrease of CD80 mRNA in NRK and IEC6 cells respectively,compared with negative control lentivirus.Conclusion:The recombinant lentiviral shRNA expressing vector targeting rat CD80 gene has been successfully constructed and packaged.CD80 mRNA could be down-regulated availably in NRK and IEC6 cells.

OBJECTIVETo understand the changing trend on the way of delivery since 1970s and its related factors that influencing the attitude of choice on Cesarean section (C-section) in women at child-bearing age.

METHODSA face-to-face interview was conducted anonymously in pregnant and lying-in women visited at the out-patient department of Gynecology and Obstetrics, Tiantan Hospital of Beijing. Totally, 415 women at child-bearing age, with a history of previous birth were interviewed on date, place and way of delivery of last birth, as well as on information that could have had impact on the choice of C-section.

RESULTSThe average rate of C-section in Tiantan Hospital had been 29% since the year of 2000, much higher than that during 1970s, 1980s and 1990s (chi(2) = 22.81, P = 0.001) which showed an increasing trend. Rate of C-section among lying-in women with native Beijing origin was 25.0%, significantly higher than 9.6% (chi(2) = 21.96, P = 0.000 002) that in the migrants. Lying-in women with education level of high school or above had higher chance to choose C-section than those with lower level of education (chi(2) = 43.64, P < 0.000 01). Workers, managerial staff or clerks had more chance to choose C-section than those with other occupations (chi(2) = 20.07, P = 0.01). As reported by the interviewees, 93% (70/75) of C-section in the hospital were performed and recommended by obstetricians.

CONCLUSIONRate of C-section in the hospital showed an increasing trend which suggested that intervention with health education be carried out for both pregnant women and obstetricians.

Adult ; Cesarean Section ; statistics & numerical data ; China ; epidemiology ; Delivery, Obstetric ; statistics & numerical data ; Female ; Humans ; Pregnancy ; Surveys and Questionnaires

Objective To compare two effective preparation methods for paclitaxel-loaded lipid microbubbles, and to evaluate the physiochemical properties as for acoustic activated drug delivery. Methods Paclitaxel-loaded lipid microbubbles were prepared with two methods: one was mixed with phospholipids directly (Ⅰ); the other was added in triacetin, then mixed with phospholipids (Ⅱ). Concent ration, size, pH, drug entrapment efficiency, drug-loading amounts of these two kinds of paclitaxel-loaded lipid microbubbles were studied, while drug release with ultrasound and tumor imaging enhanced on rabbit breast tumor were observed. Results There was no significant difference in tumor imaging between two kinds of microbubbles which could be ruptured by low energy ultrasound. Compared with Ⅰ, the mean diameter of Ⅱ decreased significantly ([ 1.07±0.38] μm vs [2.79± 0.41] μm, P<0.01), the surface potencial was higher ([19.10±0.32] mV vs [-5.90±0.21] mV, P<0.01), whereas entrapment efficiency and drug-loading amounts increased markedly ([ 95.00±1.22]% vs [36.10±4.74]%, P<0.01; [5.60±0.11]% vs [0.50±0.04]%, P<0.01). Conclusion The Ⅱ paclitaxel-loaded lipid microbubbles added triacetin have an important clinical value.

Objective To investigate the reversal effect of MDR1 and MDR3 gene silencing on resistance of A2780/taxol cells to paclitaxel.Methods shRNA plasmid vector specifically targeting MDR1 and MDR3 genes was transfected into A2780/taxol cells.The early stage cell apoptosis and the effect of intracellular rhodamine 123(Rh123)accumulation were detected by flow cytometry(FCM).The late stage cell apoptosis rate was detected by terminal deoxynucleotidyl transferase(TdT)-mediated deoxyuridine triphosphate(dUTP)nick end labeling(TUNEL).The 50% inhibition concentration(IC_(50))of paclitaxel on A2780/taxol cells was determined by methyl thiazolyl tetrazolium(MTT)assay.MDR1 and MDR3 mRNA were assessed by RT-PCR,and caspase-3 protein was detected by western blot.Results After treatment with MDR1 and MDR3 shRNA plasmid vector,early apoptosis rate of A2780/taxol cells was (20.21?0.56)% and(10.87?1.24)%,respectively.MDR1 and MDR3 shRNA could increase cellular Rh123 accumulation(116.6?8.1 and 98.4?3.8,respectively).The late stage apoptosis rates detected by TUNEL displayed the same tendency as FCM results did.The IC_(50)for paclitaxel of A2780/taxol cells was decreased significantly.The mRNA levels of MDR1 and MDR3 in A2780/taxol cells were decreased by (73.3?0.8)% and(51.6?0.4)% of control,and the reduction of MDR1 and MDR3 mRNA was in a time-dependent manner.The expression of caspase-3 protein of MDR1 and MDR3 shRNA vector transfected group in A2780/taxol cells was significantly increased [(80.8?2.6)% and(72.0?4.7)%, respectively ].Conclusion MDR1 and MDR3 gene silencing could recover sensitivity of A2780/taxol cells to paclitaxel and induce cell apoptosis,thus reversing cell resistance to paclitaxel.

OBJECTIVETo investigate the features and duration of viral nucleic acid shedding in children with influenza A.

METHODSThe clinical data of 90 children with influenza A with positive influenza A virus nucleic acid in nasopharyngeal swab detected by PCR were collected, and these children were divided into simple influenza A group (n=10), influenza A-pneumonia group (n=61), influenza A-nervous system damage group (n=10), and influenza A-underlying disease group (n=9). A retrospective analysis was performed for clinical features, treatment process, duration of viral nucleic acid shedding, and prognosis.

RESULTSThe most common symptoms in these children were fever (89/90, 99%), cough (89/90, 99%), running nose (69/90, 77%), shortness of breath (26/90, 29%), and myalgia (23/90, 26%). The mean duration of viral nucleic acid shedding in 90 children was 9.4±2.9 days. The simple influenza A group had a significantly shorter duration of viral nucleic acid shedding than the influenza A-pneumonia, influenza A-nervous system damage, and influenza A-underlying disease groups (p<0.05), while there were no significant differences between the influenza A-pneumonia, influenza A-nervous system damage, and influenza A-underlying disease groups (p>0.05). The children who received antiviral therapy within 48 hours after disease onset had significantly shorter duration of viral nucleic acid shedding and time to body temperature recovery than those who received antiviral therapy more than 48 hours after disease onset (p<0.05). Of all the children with body temperature recovery, 83% still tested positive for viral nucleic acid.

CONCLUSIONSComplications, underlying diseases, and timing of antiviral therapy are influencing factors for the duration of influenza A virus nucleic acid shedding, and whether body temperature returns to normal cannot be used to decide whether to continue antiviral therapy.

Child ; Child, Preschool ; Female ; Fever ; etiology ; Humans ; Infant ; Influenza A virus ; isolation & purification ; Influenza, Human ; virology ; Male ; Nucleic Acids ; metabolism ; Retrospective Studies ; Time Factors ; Virus Shedding

Objective To study the cerebral infarction subtypes and brain perfusion abnormalities in patients with middle cerebral artery occlusive disease (MCAOD) based on findings in neuroradiological imaging. Methods In 116 MCAOD cases confirmed by CT angiography (CTA), the data of plain CT scanning, CT perfusion imaging, and CTA were retrospectively analyzed to identify the cerebral infarction subtypes and brain perfusion abnormalities. Results In the 116 cases enrolled in this study, CTA detected 133 middle cerebral arteries (MCA) with stenotie or occlusive lesions, which involved unilateral MCA in 99 cases and bilateral MCA in 17 cases. Severe MCAOD were found in 64 cases (including 25 with MCA occlusion and 39 with severe MCA stenosis), and moderate and mild MCA stenosis in 69 cases. CT or magnetic resonance imaging (MRI) identified multiple lacunar infarctions in 45 cases, territorial infarctions in 26 cases, watershed infarctions of different types in 38 cases, striatocapsular infarctions in 10 cases and no infarction associated with the stenotic MCA in 14 cases. CT perfusion imaging showed hypoperfusion areas in 96 cases (72.2%), including 58 cases with perfusion abnormalities involving large areas in the territory supplied by the MCA; no perfusion abnormalities were found in 37 cases. Conclusion According to the severity and location of MCA stenosis, pathogenesis of stroke and the establishment of collateral circulation, MCAOD may cause different types of cerebral infarction and brain perfusion abnormalities.

Ginseng is a traditional Chinese medicine which has been used in treating anemia for thousands of years. It is composed of a lot of components. The main component is total saponin of panax ginseng (TSPG), which contains more than 20 ginsenosides including Rg1, Rb1 and so on. Previous studies have reported that total saponin of panax ginseng could promote hematopoiesis by stimulating proliferation of human erythroid grogenitor cells CFU-E and BFU-E, however, it had different effects on CFU-GM reported by various laboratories. In this study, CFU-GM assay was adopted to observe the ginsenosides Rg1 and Rb1's effects on the proliferation of human marrow grannulocyte-macrophage progenitor cells. The results showed that Rg1 and Rb1 had obvious promotive effect on the proliferation of CFU-GM, and the increasing rates of colony formation were up to (70.6 +/- 6.8)% and (65.1 +/- 6.3)%, respectively. There was no inhibiting effect on CFU-GM in high concentrations of Rg1 and Rb1. It is suggested that Rg1 and Rb1 can stimulate the proliferation of human granulocyte-macrophage progentors. The results of TSPG's various effects on CFU-GM might be caused by different contents of ginsenosides in TSPG used in different laboratories.

The object of this study was to explore the effects of Panax notoginosides (PNS) on proliferation and differentiation of human CD34(+) stem/progenitor cells. CD34(+) cells were isolated from human bone marrow by using immune beads of Dynal M- 450 system. The cells were exposed to PNS at different concentrations in both liquid and semi-solid culture for 14 days. The cells were marked with monoclonal antibodies and analyzed by flow cytometry after culture. The CFU-Mix colony formation from CD34(+) cells was assayed. The results showed that: (1) The yield of CD34(+) cells after being selected by immune beads were (1.03 +/- 0.74)% out of bone marrow nuclear cells with purity of 86% - 93%. (2) PNS (10 - 25 mg/L) stimulated the proliferation of CD34(+) cells, and raised the colony numbers of CFU-Mix obviously in vitro. PNS 25 mg/L was the optimal concentration to promote proliferation of CD34(+) cells, the increasing rate of CFU-Mix colony was (34.7 +/- 16.0)%. (3) The differentiation of CD34(+) cells was induced by exposure to PNS (25, 50 and 100 mg/L) in liquid culture for 14 days. The percentages of CD33(+) and CD15(+) cells were increased after PNS exposure, which were significantly higher than those of control (P < 0.01), however CD71(+) and G-A(+) cells were no obviously difference after PNS treatment. In conclusion, Panax notoginosides not only promote the proliferation of CD34(+) cells, but also induce the differentiation committed to granulocytes.
Antigens, CD ; analysis ; Antigens, CD34 ; analysis ; Antigens, Differentiation, Myelomonocytic ; analysis ; Cell Differentiation ; drug effects ; Cell Division ; drug effects ; Ginsenosides ; pharmacology ; Hematopoietic Stem Cells ; cytology ; drug effects ; Humans ; Lewis X Antigen ; analysis ; Sialic Acid Binding Ig-like Lectin 3