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.

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 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.

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 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.

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.

This study is to investigate the therapeutic effect and mechanism of indole-3-carbinol (I3C) on pig serum-induced liver fibrosis of rats. The liver fibrotic model of rats was induced by pig serum. After models were successfully established, rats in the treatment groups were administered with I3C through intraperitoneal injection or curcumin by intragastric administration, daily for 17 days. Hepatic hydroxyproline (Hyp) content was measured. The liver histology and immunohistochemistry with a-smooth muscle actin (alpha-SMA) were assayed. Hepatic stellate cells line, HSC-T6 was incubated with different concentrations of I3C (25, 50, and 100 micromol x L(-1)) for 24 h. The effect of I3C on cell apoptosis was identified by FITC-Annexin V/PI double labeled assay. And the mRNA expressions of Bax and Bcl-2 were measured by real time RT-PCR. The results showed that hepatic content of Hyp decreased by I3C treatment, as compared with the fibrotic model control. Histopathological changes, such as steatosis, necrosis, deposition of collagenous fiber reduced remarkably and the expression of alpha-SMA was significantly down-regulated in the I3C-treated groups (P < 0.01). Apoptosis analysis showed that I3C significantly increased HSC-T6 apoptosis rate and the expressional ratio of Bax to Bcl-2. The results indicated that I3C could effectively cure pig serum-induced liver fibrosis in vivo by inducing HSC apoptosis and promoting ECM degradation.
Actins ; metabolism ; Animals ; Apoptosis ; drug effects ; Cell Line ; Collagen ; metabolism ; Curcumin ; pharmacology ; Enzyme Inhibitors ; pharmacology ; Hepatic Stellate Cells ; cytology ; Hydroxyproline ; metabolism ; Indoles ; pharmacology ; Liver ; metabolism ; pathology ; Liver Cirrhosis, Experimental ; metabolism ; pathology ; Male ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Rats ; Rats, Wistar ; Serum ; Swine ; blood ; bcl-2-Associated X Protein ; genetics ; metabolism

OBJECTIVETo determine the molecular basis of late onset ornithine transcarbamylase (OTC) deficiency in a Chinese family of Han nationality and the exon sequences of OTC gene of this patient.

METHODSPolymerase chain reaction-single strand conformation polymorphism and direct sequencing were used to identify the mutation type.

RESULTSA missense mutation E122G in the conserved residue of exon 4 was identified which is unreported before.

CONCLUSIONThe E122G mutation in human OTC gene may cause late onset OTC deficiency.

Age of Onset ; Base Sequence ; Child, Preschool ; DNA ; chemistry ; genetics ; DNA Mutational Analysis ; Family Health ; Fatal Outcome ; Female ; Humans ; Male ; Models, Molecular ; Mutation, Missense ; Ornithine Carbamoyltransferase ; chemistry ; genetics ; Ornithine Carbamoyltransferase Deficiency Disease ; enzymology ; genetics ; pathology ; Pedigree ; Polymorphism, Single-Stranded Conformational ; Protein Structure, Secondary

Tumors often have DNA repair defects, suggesting additional inhibition of other DNA repair pathways in tumors may lead to synthetic lethality. Accumulating data demonstrate that DNA repair-defective tumors, in particular homologous recombination (HR), are highly sensitive to DNA-damaging agents. Thus, HR-defective tumors exhibit potential vulnerability to the synthetic lethality approach, which may lead to new therapeutic strategies. It is well known that poly (adenosine diphosphate (ADP)-ribose) polymerase (PARP) inhibitors show the synthetically lethal effect in tumors defective in BRCA1 or BRCA2 genes encoded proteins that are required for efficient HR. In this review, we summarize the strategies of targeting DNA repair pathways and other DNA metabolic functions to cause synthetic lethality in HR-defective tumor cells.
Animals ; Antineoplastic Agents ; pharmacology ; Breast Neoplasms ; genetics ; DNA Repair ; drug effects ; genetics ; Gene Expression Regulation, Neoplastic ; drug effects ; Genes, Lethal ; genetics ; Genes, Tumor Suppressor ; drug effects ; Genes, cdc ; drug effects ; Humans ; Mutagenesis ; Poly(ADP-ribose) Polymerase Inhibitors ; Rad52 DNA Repair and Recombination Protein ; antagonists & inhibitors ; Recombination, Genetic ; drug effects ; genetics

OBJECTIVETo study the effects of extracts of ginkgo biloba (EGB) on the levels of nitric oxide (NO) and apoptosis in the retina induced by glutamate by intravitreal injection in adult rabbit.

METHODThe model of apoptosis in retina induced by glutamate by intravitreal injection was established in adult rabbit and EGB was retrobulbarly injected. The levels of NO were measured by spectrophotometer. Retina DNA fragmentation was determined by agarose gel electrophoresis.

RESULTThe levels of NO in retina in experiment groups were significantly increased compared with controls, after treatment with high dosage of EGB, and levels of NO was decreased to normal. They were not decreased by injection of small dosage of EGB. DNA fragmentation of retina apoptosis was detected in experiment groups and small dosage EGB groups.

CONCLUSIONThe retina apoptosis was induced by glutamate by intravitreal injection in adult rabbit and was inhibited by EGB that may be through blocking the generation of NO free radicals.

Animals ; Apoptosis ; drug effects ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Female ; Ginkgo biloba ; chemistry ; Glutamic Acid ; Male ; Nitric Oxide ; metabolism ; Plant Leaves ; chemistry ; Plants, Medicinal ; chemistry ; Rabbits ; Random Allocation ; Retina ; cytology ; metabolism