Chinese medical sciences journal = Chung-kuo i hsueh k'o hsueh tsa chih最新文献

Objective: To investigate the expression profile of microRNA-21 in human cholangiocarcinoma tissues and to validate its bona fide targets in human cholangiocarcinoma cells.

Methods: The expression profile of microRNA-21 in human cholangiocarcinoma tissues and cholangiocarcinoma cell line, QBC939, was evaluated by using real-time PCR analysis. The bona fide targets of microRNA-21 were analyzed and confirmed by dual luciferase reporter gene assay and western blot, respectively. The expressional correlation of microRNA-21 and its targets was probed in human cholangiocarcinoma tissues by using real-time PCR, locked nucleic acid in situ hybridization (LNA-ISH), and immunohistochemistry analysis.

Results: Real-time PCR analysis revealed that microRNA-21 expression depicted a significant up-regulation in human cholangiocarcinoma tissues about 5.6-fold as compared to the matched normal bile duct tissues (P<0.05). The dual luciferase reporter gene assay revealed endogenous microRNA-21 in cholangiocarcinoma cell line, QBC939, inhibited the luciferase reporter activities of wild-type PTEN (P<0.01) and PDCD4 (P<0.05) and had no this effect on mutated PTEN and PDCD4. Moreover, loss of microRNA-21 function led to a significant increase of PTEN and PDCD4 protein levels in QBC939 cells. Elevated microRNA-21 levels were accompanied by marked reductions of PTEN and PDCD4 expression in the same cholangiocarcinoma tissue.

Conclusion: microRNA-21 expression is up-regulated in human cholangiocarcinoma and PTEN, PDCD4 are direct effectors of microRNA-21.

Objective: To retrospectively investigate the distribution in kidney transplantation for fifteen years in Peking Union Medical College Hospital.

Methods: We conducted a descriptive research counting up the number of patients who received kidney transplantation each year in our hospital during 1995 and 2010.

Results: The first kidney transplantation in our hospital occurred in the 1960s. The number of kidney transplantation increased until reaching a maximum of 47 grafts in 2001; since then the number fell.

Conclusions: With the decreased number of kidney transplantation, we have realized the shortage of transplantable organs is very serious. The continuing transplant shortage requires major efforts to expand the donor pool. Donation after cardiac death offers the potential to enlarge the donor pool, but we need to strictly control the criteria for potential donors.

Objective: To investigate whether multiple coatings can improve the bond durability of one-step self-etching adhesive to primary dentin.

Methods: Twelve caries-free human primary molars were randomly divided into 2 groups. In group 1, each tooth was hemisected into 2 halves. One half was assigned to the control subgroup 1, which was bonded with a commercially available one-step self-etching adhesive according to the manufacturer's instructions; the other half was assigned to experimental subgroup 1, in which the adhesive was applied three times before light curing. In group 2, one split half tooth was bonded with a commercially available one-step self-etching adhesive according to the manufacturer's instructions; for the other half, three layers of adhesive were applied with each successive layer of light curing. Specimens were stored in 0.9% NaCl containing 0.02% sodium azide at 37℃ for 18 months and then were subjected to microtensile bond strength test and the fracture mode analysis.

Results: When the adhesive was applied three times before light curing, the bond strength of the experimental subgroup 1 was significantly higher than that of the control subgroup 1 (47.46∓13.91 vs. 38.12∓11.21 MPa, P<0.05). When using the technique of applying multiple layers of adhesive with each successive layer of light curing, no difference was observed in bond strength between the control subgroup and the experimental subgroup (39.40±8.87 vs. 40.87±9.33 MPa, P>0.05).

Conclusion: Multiple coatings can improve the bond durability of one-step self-etching adhesive to primary dentin when using the technique of light-curing after applying 3 layers of adhesive.

Objective: To retrospectively investigate the clinical characteristics of sternal insufficiency fractures (SIFs) of post-menopausal women.

Methods: Findings on the clinical presentation, associated diseases, and imaging of SIFs in 17 postmenopausal women admitted to our hospital between February 1999 and January 2009 were reported.

Results: Twelve patients complained of severe pain in their anterior chest. Other symptoms included cough (5 cases), dyspnoea (3 cases), breathlessness (3 cases), and wheeze (2 cases). Four patients had no discomfort. The sternums of 11 cases were tender to palpation. Seventeen patients had osteoporosis. Other associated diseases were chronic obstructive pulmonary disease (7 cases), rheumatoid arthritis (3 cases), systemic lupus erythematosus (1 case), asthma (1 case), and thoracic vertebral fracture (13 cases). Nine patients had received glucocorticoid treatment. The fractures were located in the body of the sternum in 15 patients, in the manubrium in 1 patient, and in the manubriosternal junction in 1 patient. Displaced fracture was present in 13 cases. Lateral radiography of the sternum showed a fracture line in 14 patients. In the remaining 3 cases, other imaging examinations such as bone scan, computed tomography or magnetic resonance imaging demonstrated the presence of a fracture.

Conclusions: Osteoporosis, glucocorticoid therapy, chronic obstructive pulmonary disease, and rheumatoid arthritis might be risk factors for SIFs. SIFs should be considered in the differential diagnosis of chest pain.

Objective: To investigate the effects of rapamycin on cholesterol homeostasis of glomerular mesangial cells and the underlying mechanisms.

Methods: Intracellular cholesterol accumulation was measured by Oil Red O staining and high performance liquid chromatography. The effects of rapamycin on interleukin-1 beta (IL-1 beta)-induced mRNA and protein changes of low-density lipoprotein receptor (LDLR) and ATP-binding cassette transporter A1 (ABCA1) were assayed by quantitative real-time PCR and Western blot. Transient expressions of 3 types of mammalian target of rapamycin (mTOR), including mTOR-WT (wild type), mTOR-RR (rapamycin resistant, with kinase activity), and mTOR-RR-KD (rapamycin resistant, without kinase activity), were obtained by plasmid transfection.

Results: Rapamycin had no significant influence on intracellular cholesterol concentration under normal condition, but it significantly decreased the intracellular cholesterol concentration in the presence of IL-1 beta. Rapamycin dose-dependently suppressed the increased expression of LDLR induced by IL-1 beta and up-regulated the suppressed expression of ABCA1 caused by IL-1 beta. Transient expression of 3 types of mTOR all reduced ABCA1 mRNA expression significantly, which all could be overroded by rapamycin.

Conclusions: Rapamycin may contribute to the maintaining of glomerular mesangial cell intracellular cholesterol homeostasis under inflammatory state by both reducing cholesterol uptake and increasing cholesterol efflux. And the effect may be not completely mediated by mTOR.

Objective: To analyze how the infection of human papillomavirus 16 (HPV16) affects expression of DNA polymerase beta (DNA polB) with the aim of probing the mechanism of over-expression of DNA polB in human cancers.

Methods: Four fragments of human DNA polB promoter were amplified and constructed into luciferase reporter vector pGL-Basic, generating pGL-BP, pGL-BMH, pGL-BMS, and pGL-BAT constructs respectively, and co-transfected with HPV16 or HPV6 into Hep2 cells. Luciferase activity was assayed 48 hours after transfection. Semi-quantitative RT-PCR was used to measure mRNA expression of endogenous DNA polB. Immunohistochemistry and in situ hybridization were used to analyze DNA polB expression and HPV16 or HPV6 infection in 38 cases of cervical lesions respectively.

Results: With co-transfection of HPV16 and DNA polB promoter-driving reporters into Hep2 cells, pGL-BP reporter in full-length DNA polB promoter presented markedly elevated luciferase activities (P < 0.05). However, the other three mutant reporters: pGL-BMH, pGL-BMS, and pGL-BAT, generated no reporting activities in the presence of HPV16 (P > 0.05). On the contrary, all of polB promoter reporters were little stimulated in co-transfection of HPV6 (P > 0.05). The transfection of HPV16 could enhance the endogenous polB mRNA expression compared with that of HPV6 (3.42 vs. 0.80, P < 0.05). The DNA polB expression was found in 8 of 10 HPV16-positive cervical intraepithelial neoplasia grade III (CIN III) cases, while was only found in 3 of 11 HPV6-positive condyloma accuminatum cases, but was negative in all chronic cervicitis cases. The correlation of DNA polB expression with HPV16 infection in cervical lesions was significant (P < 0.05).

Conclusions: HPV16 is able to specifically stimulate the expression of DNA polB in human epithelial cells through interaction with the core upstream regulatory sequences of DNA polB promoter. Over-expression of DNA polB might be an explanation for the molecular mechanism underlying HPV-related human cancers.

Objective: To investigate the frequency of GAG deletion in the DYT1 gene among early onset primary dystonia patients in China.

Methods: Thirteen patients with early onset primary torsion dystonia were screened for mutation in exon 5 of the DYT1 gene using denaturing high-performance liquid chromatography (DHPLC) and DNA sequencing, and the results were confirmed with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

Results: The GAG deletion mutation which results in Glu302del in exon 5 of the DYT1 gene was found in 5 patients. The detecting results were consistent between with DHPLC and PCR-RFLP. We did not find any other mutations in the DYTI gene.

Conclusions: The GAG deletion in the DYT1 gene is common amongst early onset primary torsion dystonia patients in China. The frequency of DYT1 mutation is not significantly different between European and Asian patients with early onset primary dystonia.