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

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.

Objective: To evaluate the efficacy and safety of long-term treatment with arotinolol in patients with idiopathic dilated cardiomyopathy (IDCM).

Methods: Sixty-three patients with IDCM were evaluated at baseline and after 12-month therapy with arotinolol. The conventional therapy for congestive heart failure was continued throughout the study with arotinolol as the only beta-blocker. Left ventricular function was assessed with the New York Heart Association functional class and two-dimensional echocardiography.

Results: After 12-month arotinolol treatment, there was a significant improvement in left ventricular systolic function. Left ventricular end-systolic dimension significantly decreased from 59.52 +/- 8.83 mm to 50.89 +/- 8.17 mm (P < 0.001). Left ventricular ejection fraction significantly increased from 27.39% +/- 7.94% to 41.13% +/- 9.45% ( P < 0.001). Left ventricular mass index decreased from 150.47 +/- 42.42 g/m2 to 141.58 +/- 34.36 g/m2 (P < 0.01). No adverse events leading to premature discontinuation of study drug occurred.

Conclusion: In this preliminary study, 12-month arotinolol treatment has a favorable effect on left ventricular function in patients with IDCM, and it is safe and well tolerated.