[Age-related coronary risk factors in Chinese patients with acute myocardial infarction]

Objective: To determine the age-related coronary risk factors in Chinese patients with acute myocardial infarction (AMI). Methods: Among 31 provinces, municipalities or autonomous districts in China, from January 1st 2013 to September 30th 2014, 24 394 consecutive AMI patients who were admitted to 107 hospitals were divided into five groups according to age. Cardiovascular risk factors of groupⅠ (<45 years, n=2 307), group Ⅱ (45-54 years, n=4 448), group Ⅲ (55-64 years, n=7 029), group Ⅳ (65-74 years, n=6 147) and group Ⅴ (≥75 years, n=4 463) patients were compared. Results: Among 24 394 AMI patients [with a mean age of (62.2±13.8) years, 18 162 males], 24.7% patients had three and more conventional modifiable cardiovascular risk factors. ST-elevation myocardial infarction (STEMI) was diagnosed in 18 209 (74.6%) patients. The ratios of female, hypertension and diabetes tended to increase with the increase of age. Young AMI patients were predisposed to smoking, overweight/obesity and hyperglycemia. Nearly 90% patients in group Ⅰ and group Ⅱ were male. The ratio of male patients (92.3% to 58.0%), overweight/obesity (63.9% to 37.4%), current smoking (68.7% to 19.8%), dyslipidemia (9.1% to 4.5%), family history of premature coronary artery disease (CAD) (6.2% to 1.2%) and eating greasy food (86.1% to 66.2%) decreased markedly from group Ⅰ to Ⅴ patients. Proportion of hypertension gradually increased from 34.3% in group Ⅰ patients to 57.9% in group Ⅴ patients. Diabetes was most common to group Ⅳ (65-74 years) patients. Conclusion: There were different risk factors for AMI patients in different age groups, and young AMI patients were predisposed to live an unhealthy lifestyle.

[Relationship between shift work and overweight/obesity in male steel workers]

Objective: To investigate the relationship between shift work and overweight/obesity in male steel workers. Methods: A questionnaire survey was conducted among the male steel workers selected during health examination in Tangshan Steel Company from March 2015 to March 2016. The relationship between shift work and overweight/obesity in the male steel workers were analyzed by using logistic regression model and restricted cubic splinemodel. Results: A total of 7 262 male steel workers were surveyed, the overall prevalence of overweight/obesitywas 64.5% (4 686/7 262), the overweight rate was 34.3% and the obesity rate was 30.2%, respectively. After adjusting for age, educational level and average family income level per month by multivariable logistic regression analysis, shift work was associated with overweight/obesity and obesity in the male steel workers. The OR was 1.19(95% CI: 1.05-1.35) and 1.15(95% CI: 1.00-1.32). Restricted cubic spline model analysis showed that the relationship between shift work years and overweight/obesity in the male steel workers was a nonlinear dose response one (nonlinear test χ²=7.43, P<0.05). Restricted cubic spline model analysis showed that the relationship between shift work years and obesity in the male steel workers was a nonlinear dose response one (nonlinear test χ²=10.48, P<0.05). Conclusion: Shift work was associated with overweight and obesity in the male steel workers, and shift work years and overweight/obesity had a nonlinear relationship.

Sesamol attenuates oxidative stress, apoptosis and inflammation in focal cerebral ischemia/reperfusion injury

The aim of the present study was to evaluate the therapeutic potential of sesamol treatment on focal ischemia/reperfusion (I/R) injury in the rat brain. The results demonstrated that pretreatment with sesamol seven days prior to focal cerebral I/R injury had significant positive effects, including improvements in neurological deficits (P<0.05), and a reduction in malondialdehyde content and elevation of antioxidant levels (superoxide dismutase, glutathione and glutatione peroxidase; both P<0.05). Furthermore, levels of B cell lymphoma-2 (Bcl-2)-associated X protein and caspase-3 were significantly downregulated, whereas the level of Bcl-2 was effectively increased. Conversely, the mRNA expression of proinflammatory cytokines were significantly reduced in focal cerebral I/R injury rats upon sesamol intervention. Therefore, the beneficial effects of sesamol on cerebral I/R injury may be due to the reduction of oxidative stress, inhibition of apoptosis and inflammation. The findings of the present study suggest that sesamol supplementation may serve as potent adjuvant in the treatment of focal cerebral ischemia/reperfusion injury due to its neuroprotective effects.

[Influence of Coca-Cola on early erosion and surface microhardness of human enamel: an in situ study]

OBJECTIVE

Assessed the effect of single dose attack of Coca-Cola on early erosion and surface microhardness of permanent human enamel, in order to provide diet instructions on minimum amount and frequency of carbonated beverage consumption.

METHODS

Eighty enamel slabs were prepared out of 10 extracted human mandibular third molars, and distributed into 8 groups with randomized block design(n=10). Ten generally healthy volunteers with normal saliva secretion wore acrylic palatal appliances containing 2 enamel slabs, with formation of a salivary pellicle 2 h ahead. The volunteers were instructed to drink 100 ml fresh Coca-Cola within 20 s. And then the alterations of the enamel slabs were measured using a Vicker's microhardness tester at 1, 2, 4, 6, 8, 10, 20 and 30 min after the consumption of Coca-Cola. For each volunteer, the experiment was carried out in four days, 2 samples were examined each time. Data were analyzed using Kruskal-Wallis and Wilcoxon tests(α =0.05).

RESULTS

Significant decreases in surface microhardness(SMH)were observed in each time point(P<0.01). The percentages of surface microhardness changes on each exposure time were(12.2±3.9)%,(16.8±5.5)%,(16.7±5.6)%,(16.2±6.2)%,(16.6±9.0)%,(15.6±3.7)%,(13.8±4.8)% and(11.4±3.2)%, respectively. Significant differences were observed between G1 min and G2-8 min(P=0.029), G2-8 min and G30 min(P=0.008).

CONCLUSIONS

Single intake of 100 ml Coca-Cola could lead to significant decrease of enamel microhardness and initiate erosion of enamel surface. Enamel surface microhardness decreased to the lowest points at 2-8 min, and began to recover after 10 min. The enamel surface microhardness could not fully recovered to the baseline level in 30 min if no intervention was performed.

Monocyte chemoattractant protein-1 contributes to morphine tolerance in rats with cancer-induced bone pain

Cancer-induced bone pain can severely compromise the life quality of patients, while tolerance limits the use of opioids in the treatment of cancer pain. Monocyte chemoattractant protein-1 (MCP-1) is known to contribute to neuropathic pain. However, the role of spinal MCP-1 in the development of morphine tolerance in patients with cancer-induced bone pain remains unclear. The aim of the present study was to investigate the role of spinal MCP-1 in morphine tolerance in bone cancer pain rats (MTBP rats). Bone cancer pain was induced by intramedullary injection of Walker 256 cells into the tibia of the rats, while morphine tolerance was induced by continuous intrathecal injection of morphine over a period of 9 days. In addition, anti-MCP-1 antibodies were intrathecally injected to rats in various groups in order to investigate the association of MCP-1 with mechanical and heat hyperalgesia using the paw withdrawal threshold (PWT) and thermal withdrawal latency (TWL) tests, respectively. Furthermore, MCP-1 and CCR2 expression levels were measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis, and CCR2 expression levels were measured using RT-qPCR. The results indicated that MCP-1 and CCR2 expression levels were significantly increased in the spinal cord of MTBP rats. Intrathecal administration of anti-MCP-1 neutralizing antibodies was observed to attenuate the mechanical and thermal allodynia in MTBP rats. Therefore, the upregulation of spinal MCP-1 and CCR2 expression levels may contribute to the development of mechanical allodynia in MTBP rats. In conclusion, MCP-1/CCR2 signaling may serve a crucial role in morphine tolerance development in rats suffering from cancer-induced bone pain.

[Rheumatoid arthritis involving tibialis posterior tendon: study on the early diagnostic value of power Doppler ultrasonography and comparison with surgery]

Objective: To explore the value of power Doppler ultrasonography (PDUS) in the early diagnosis of tibialis posterior tendon injury induced by rheumatoid arthritis (RA). Method: From January 2014 to December 2015, a total of 48 cases (60 feet) of RA tendinopathy group were selected as the research subjects from Guanghua Hospital; 12 cases(20 feet) of non-RA tendinopathy group and 10 cases (20 feet) of healthy volunteers were selected as control group.The blood flow signals of pannus were observed by PDUS to determine whether the tendon was injured or the degree of the injury. The following indexes were compared and analyzed by Chi-square testing: (1)positive rate of blood flow signal; (2)grade of blood flow signal; (3)spatial distribution of blood flow signal: diffusibility or local. Results: Of 70 cases(100 feet) in the study, the positive blood flow signals were only in the RA(88.3%) and non-RA group(40.0%) .Grade Ⅲ in RA was 20.0%, while this was not observed in non-RA . Grade Ⅱ in RA and non-RA was 36.7% and 10.0% , respectively. There were significant differences in the positive rate and grades between RA and non-RA group (P<0.01). The spatial distribution of blood flow signal in RA was significantly different from that in non-RA. In RA, they can be detected in the whole tendon.However, they were mainly distributed around the scaphoid in non-RA. In this study, three patients with grade Ⅲwere treated with surgery. The intraoperative findings were consistent with the preoperative ultrasound results. Conclusions: PDUS can be used to detect the neovascular formation of tendon synovitis. It can detect the early tendon injury before the appearance of foot deformity induced by RA, which can guide clinical early intervention treatment and prevent the occurrence of deformity and other serious consequences.

[Effect of root canal sealers on biocompatibility of human periodontal ligament cells]

OBJECTIVE

To compare the effects of three root canal sealers with respect to time on biocompatibility of human periodontal ligament cells (hPDLCs).The sealers included zinc oxide and eugenol based sealers (ZOE), epoxy resin sealers (ERS) and silicone based sealers (SBS).

METHODS

hPDLCs were primarily cultured,with the method combining of tissue explant and enzymatic digestion. The cells were then exposed to different extract fluids: (1) ZOE extracted for 24 h group ;(2) ZOE extracted for 1 week group;(3)ZOE extracted for 2 weeks group;(4) ERS extracted after 24 h group; (5) ERS extracted after 1 week group; (6) ERS extracted after 2 weeks group; (7) SBS extracted after 24 h group; (8) SBS extracted after 1 week group; (9) SBS extracted after 2 weeks group; (10) Dulbecco modified Eagle's medium/F12 (DMEM/F12) as negative control group. Cell morphology was observed under an inverted microscope.Cell proliferation was measured by methyl-thiazol-diphenyltetrazolium (MTT) assay. ALP assay kit was used for measuring alkaline phosphatase (ALP) activity. Sealers of 2 weeks' setting time were then immersed in an osteogenic medium for examination of mineral nodules and calcium deposits.

RESULTS

Considering the relative growth rate(RGR),ZOE was severely to moderately cytotoxic(RGR:13.6%-39.9%), while ERS was slightly or not cytotoxic (RGR: 87.6%-95.3%).Only SBS did not show any cytotoxicity after setting (RGR: 91.8%-106.7%). The setting time influenced the cytotoxicity of ERS which decreased after 1 week. Considering the ALP activity,there was no difference between SBS group and control group (F=3.397,P=0.053). According to the results of calcium deposits, ZOE:D562 nm=0.180±0.050,ERS: D562 nm=2.968±0.201,SBS:D562 nm=3.623±0.039,Control:D562 nm=3.477±0.102,the ranking of ALP activity and calcium deposits was as follows: ZOE<ERS <SBS=Control.

CONCLUSION

The cytotoxicity of ZOE was the highest and persisted with time. The setting time had influence on the cytotoxicity of ERS. Only SBS did not show any cytotoxicity or inhibition of the mineral potential on hPDLCs, indicating which was more biocompatible than the others.

[Survey of medical care resources of acute myocardial infarction in different regions and levels of hospitals in China]

OBJECTIVE

To investigate the medical care resources of acute myocardial infarction (AMI) in Chinese hospitals of different regions and levels.

METHODS

We selected 115 hospitals in China, including 61 northern hospitals, 54 southern hospitals, 52 eastern hospitals, 26 central hospitals, 37 western hospitals, 79 tertiary hospitals, 36 secondary hospitals, 34 pro vincial-level hospitals, 46 prefectural-level hospitals and 35 county hospitals. From November 2012 to August 2013, we sent questionnaire to the cardiologists in each hospital, to collect related information.

RESULTS

(1) The number of AMI admitted each year of northern hospital was more than the number of southern hospital (220 (120, 400) cases vs. 220 (80, 350) cases, P=0.033), while number of coronary care unit (CCU), thrombolytic therapy, percutaneous coronary intervention (PCI), primary PCI and coronary artery bypass grafting (CABG) were similar (all P> 0.05). (2) The number of AMI admitted each year of eastern, central and western hospital was 295(150, 501) cases, 175(75, 300) cases and 170(50, 250) cases respectively(P=0.007), with no significant difference among them for setting CCU, carrying out thrombolytic therapy, PCI, primary PCI and CABG (all P>0.05). (3) The total number of the in-patient beds and AMI admitted each year of tertiary hospitals were significantly higher than that in the secondary hospitals(104(70, 152)vs. 47(30, 52), P<0.001) and (300(200, 460)cases vs.80(47, 135)cases, P<0.001) respectively. There was a significant difference between tertiary and secondary hospitals for the number of CCU (97.5% (77/79)and 75.0%(27/36)), PCI (98.7%(78/79)and 27.8%(10/36)), primary PCI (96.2%(76/79)and 22.2%(8/36)), CABG (81.0%(64/79)and 11.1%(4/36)), intra-aortic balloon pump (IABP) (91.1%(72/79) and 13.9%(5/36)) respectively (all P<0.001). (4) There were obvious differences among provincial-level, prefectural-level and country-level hospitals for the admitted AMI patient numbers annually which was 400(250, 600), 232(100, 380)and 80(50, 162)cases, CCU proportion which was 100 %(34/34), 95.7%(44/46) and 74.3%(26/35), thrombolytic therapy proportion which was 88.2%(30/34), 100%(46/46)and 91.4%(32/35), PCI proportion which was 100%(34/34), 89.1%(41/46)and 37.1%(13/35), primary PCI proportion which was 100%(34/34), 84.8%(39/46)and 31.4%(11/35), CABG proportion which was 97.1%(33/34), 67.4%(31/46) and 11.4%(4/35)respectively (P<0.01 or 0.05) .

CONCLUSIONS

Different regional hospitals have no significant difference in number of CCU and reperfusion therapies, while there is a big difference on medical care resources of AMI between different-level hospitals, which may affect the diagnosis and treatment effect of patients with AMI. Clinical Trail Registry: National Institutes of Health, NCT01874691.

Effect of tumor necrosis factor-induced protein 8 on T-cell-mediated immunity in mice after thermal injury

Tumor necrosis factor-induced protein 8(TNFAIP8), the first identified member of the TNFAIP8 family, shares considerable sequence homology with members of this family. It is expressed in a wide variety of human normal tissues, with relatively higher levels in lymphoid tissues and placenta. The present study was designed to examine the effect of TNFAIP8 on T-cell-mediated immunity secondary to burn injury. Sixty male mice were randomly divided into four groups as follows: sham burn group, burn group, burn with TNFAIP8-siRNA transfection group, and burn with negative control transfection group, and they were sacrificed at designated time points. CD4+ T cells were isolated using MACS microbeads. T-Cell proliferation was analyzed with MTT assay, and IL-2, soluble IL-2R, IL-4, interferon-γ (IFN-γ) were determined with enzyme-linked immunosorbent assay kits. It was found that CD4+ T lymphocyte proliferative activity was significantly down-regulated when TNFAIP8 gene was silenced by siRNA in mice at 24 h post burn. Down-regulation of TNFAIP8 can significantly decrease expression levels of IL-2 and soluble IL-2R at 24 h after thermal injury. These results demonstrated that TNFAIP8 appeared to be involved in the immune regulation of CD4+ T lymphocytes, and the decreased expression of TNFAIP8 could affect T lymphocyte functions after thermal injury.

[Comparison of periapical radiography and cone-beam computed tomography in endodontic treated teeth for assessment of periapical lesions]

OBJECTIVE

To compare the assessments of the presence or absence and the changes of post-treatment periapical lesions using periapical radiographs versus cone-beam computed tomography (CBCT).

METHODS

Imaging records were selected from a sample of 233 radiographic examinations (including periapical radiographs and CBCT) of patients with chronic apical periododontitis who received treatment and review in Department of Cariology and Endodontology of Peking University School of Stomatology. After testing the inter-observer and intra-observer agreement, two observers determined the presence or absence of a periapical lesion and classified the changes of lesions in 4 categories: absence, reduction or enlargement of lesion, or uncertain. The differences between CBCT and periapical radiographs in detecting the presence or absence and the changes of periapical lesions were compared using McNemar test and Fisher's exact test respectively.

RESULTS

In the study, 233 teeth were assessed with both periapical radiographs and CBCT images. Periapical lesions were detected in 178 teeth on CBCT scans and in 146 teeth on periapical radiographs. CBCT images revealed a significantly larger number of lesions than were revealed by periapical radiographs (P<0.01). There was disagreement on the changes of lesions between the two radiological technologies in 25% teeth, and the difference was statistically significant (P<0.01).

CONCLUSION

Significant differences were observed between periapical radiographs and CBCT in detection of post-treatment periapical lesions and assessment of the changes of periapical lesions.

[Age-related differences in the clinical symptoms and triggering factors among Chinese patients with acute myocardial infarction]

OBJECTIVE

To analyze the age-related differences in the clinical symptoms and triggering factors among Chinese patients with acute myocardial infarction.

METHODS

Acute myocardial infarction Patients (n=14 854) registered in the China Acute Myocardial Infarction Registry from January 2013 to March 2014 were included in this study. Patients were divided into 4 groups: <55 years old group (3 950 patients), 55-64 years old group (4 361 patients), 65-74 years old group ( 3 759 patients), and ≥75 years old group (2 784 patients). Demographic features, medical history, clinical presentation and triggering factors were obtained via electronic data capture system.

RESULTS

(1)Persistent chest pain and sweat were the major typical symptoms 66.4%(9 863/14 854) and 63.8%(9 471/14 854)) in the whole cohort. Prevalence of persistent chest pain among four groups were 73.8%(2 915/3 950), 69.2%(3 016/4 361), 63.6%(2 394/3 759) and 55.2%(1 538/2 784), and radiating pain among four groups were 36.2%(1 428/3 950), 34.1%(1 487/4 361), 30.9%(1 160/3 759)and 25.9%(722/2 784), and sweat among four groups were 70.0%(2 765/3 950), 66.5%(2 898/4 361), 61.8%%(2 323/3 759)and 53.3%(1 485/2 784), and there were statistical significance for all above symptoms among groups (all P<0.001). (2)triggering factors before acute myocardial infarction could be found in 19.4%(2 879/14 854) of the patients. Prevalence of existed triggering factors among four groups were 23.8%(941/3 950), 21.0%(914/4 361), 16.6%(625/3 759) and 14.3%(399/2 784, P<0.001). Recent excessive unhealthy lifestyles among four groups were 20.8%(196/3 950), 11.9%(109/4 361), 10.1%(63/3 759) and 9.0%(36/2 784) among the 4 groups (P<0.001).

CONCLUSIONS

Persistent chest pain and sweat are absent in nearly half of Chinese patients in ≥75 years old group. Triggering factors prior to acute myocardial infarction could be evidenced in about twenty percent patients, and which are more often in young patients. Clinical Trail Registry: National Institutes of Health，NCT018746.

[In vitro study of biological characteristics of new retrograde filling materials iRoot]

OBJECTIVE

To study the biological characteristics of new retrograde filling materials iRoot BP plus and iRoot FS.

METHODS

(1) The roots were cut into 3 mm in length, and the root canals were prepared to 1 mm in diameter, followed by being filled with iRoot BP plus, iRoot FS, or mineral trioxide aggregate (MTA). The specimens were immersed in simulated body fluid (SBF). The ability of mineralization in vitro was detected through three studies. First, the mineralization of specimens was analyzed through scanning electron microscope observations and energy dispersive X-ray spectrometer. Then, the pH of SBF was monitored using pH meter. (2) The extracts were gained by immersing blocks of iRoot BP plus, iRoot FS, and MTA (8 mm diameter and 2 mm height) into dulbecco's modified eagle medium (DMEM). The effects of the extracts on proliferation of MG63 cells were detected through MTT assay. The gene expression level of alkaline phosphatase (ALP) was analyzed by quantitative real-time PCR, and the expression of ALP activity was observed by ALP activity staining.

RESULTS

(1) The formation of minerals could be observed on the surfaces of iRoot BP plus, iRoot FS, and MTA at the end of 24 h, and there were more amounts of apatite aggregated after 14 days. The values of Ca/P ratios of apatites were 1.43, 1.39, and 1.51, respectively. (2) The pH of SBF could be raised to 8.09±0.07, 7.91±0.06, and 8.11±0.06, respectively, significantly higher than the blank. (3) The extracts of iRoot BP plus, iRoot FS, and MTA of dilutions of 1:5 and 1:10 presented no effect of proliferation of MG63 cells. (4) iRoot BP plus and iRoot FS could significantly up-regulated the levels of ALP messenger RNA expression, while there was no obvious difference in ALP staining among the iRoot BP plus, iRoot FS, MTA, and the blank.

CONCLUSION

The present study shows that iRoot has displayed good mineralization capability in vitro and capability to promote differentiation and mineralization of MG63 cells, inferring that iRoot may have good bioactivity.

[Impact of long-term continuous positive airway pressure treatment for patients with obstructive sleep apnea syndrome]

OBJECTIVE

To investigate the long-term efficacy of continuous positive airway pressure (CPAP) treatment for patients with obstructive sleep apnea syndrome (OSAS).

METHODS

This case control study was performed among 154 patients with moderate or severe OSAS between September 2009 and September 2014. Patients were divided into treatment group (n=66, 53 patients with hypertension) and control group (n=88, 67 patients with hypertension). The long-term efficacy of CPAP treatment on clinical events and blood pressure was evaluated.

RESULTS

The combined incidence of death, myocardial infarction, coronary revascularization and stroke events was 1.5% (1/66) in treatment group and 11.4% (10/88) in control group (P<0.05). CPAP treatment also led to more significant reduction in systolic blood pressure ((12.24±18.06) mmHg(1 mmHg=0.133 kPa) to (4.24±16.63) mmHg, P<0.05) in the patients with hypertension in these two groups.

CONCLUSIONS

CPAP treatment could reduce the risk of cardiovascular and neurovascular events for patients with moderate or severe OSAS.

[Transcriptome analysis of human breast cancer cell lines MCF-7 and MDA-MB- 435 by RNA-seq]

The transcriptomic profiles of human breast cancer cell lines MCF-7 and MDA-MB-435 were investigated using the next-generation RNA sequencing (RNA-Seq). The DESeq package was used to screen the differentially expressed transcripts. A total of 229 genes with a significantly differential expression in MDA-MB-435 cells as compared with MCF-7 cells were obtained. Annotation of the biological functions of these genes through the Database for Annotation, Visualization and Integrated Discovery (DAVID) v6.7 demonstrated that the 229 differentially expressed genes were mainly implicated in the biological functions related to cell adhesion and motion, antigen processing and presentation (via MHC class II), hormone response, extracellular structure organization, tissue remodeling, and cell proliferation regulation. Analysis of the individual genes demonstrated that MDA-MB-435 cells exhibited a higher tendency to metastasis and antigen processing and presentation, and lower ability to hormone response. Twenty most abundant transcripts in MDA-MB-435 cells, such as VIM, TNC, and CD74, represent its high potential for metastasis. Besides the genes previously reported to be involved in tumor metastasis and development, genes newly identified in this study could provide new clues for the diagnosis and prognosis of aggressive breast cancers.

Cut-and-paste-based cloning strategy for large gene site-directed mutagenesis

Site-directed mutagenesis is an essential technique for investigating the mechanisms of gene regulation on a molecular level, as well as for exploring post-translational modifications and functional structure at the protein level. Polymerase chain reaction combining in vitro synthesis of oligonucleotide primers allows for site-directed mutation to be performed with ease. However, site-directed mutagenesis is difficult when larger plasmids are involved. Here, we present a novel method for generating large gene site-directed mutagenesis products based on a cut-and-paste-based cloning strategy. This method uses 4 primers, incorporating relevant mutations and restriction enzyme site sequences, to generate 2 DNA fragments by polymerase chain reaction. The fragments are then ligated into TA cloning vectors. Large genes containing mutations of interest were obtained by cutting and then pasting, and then inserting one fragment into another T-vector. We demonstrated the practicality of this method by creating a G59S mutation within the p150(Glued)-encoding gene.

[Micro-CT observations of the adaptation at gingival wall in Class II restorations with different dental restorative materials]

OBJECTIVE

To evaluate the adaptation of different materials for gingival layer in Class II restorations using Micro-CT.

METHODS

Eighteen extracted human premolars were selected, and Class II cavities were prepared. The teeth were randomly divided into six groups and restored using layering technique. Six materials were used for gingival layer, including four injectable materials: Beautifil Flow Plus F00 (F00), Beautifil Flow F10 (F10), Filtek Z350 Flowable (Z350F), FujiII LC CAPSULE (Fuji), and two packable materials: BeautifilII (BF), Filtek Z350 (Z350). The restored teeth were scanned with micro-CT and the images were 3D reconstructed to evaluate the volumes and the distribution of the voids on the restoration-tooth interface of the gingival layer. The volume of the voids were statistically analyzed using nonparametric Jonckheere-Terpstra tests.

RESULTS

The volumes (mm(3)) of the voids on the restoration-tooth interface were: Z350F (0.000 15), F10 (0.000 39), F00 (0.012), Fuji (0.070), Z350 (0.16) and BF (0.20). There were significant differences between Z350F/F10 and Fuji/Z350/BF (P < 0.05). Most of the voids were found on the point-line angles of the cavities.

CONCLUSION

The voids on the restoration-tooth interface were mainly on the point-line angles of the cavities. Injectable materials with high flowablility could reduce the restoration-tooth interface voids significantly when used for the gingival layer in Class II restorations.

Opposite effects of genistein on the regulation of insulin-mediated glucose homeostasis in adipose tissue

BACKGROUND AND PURPOSE

Genistein is an isoflavone phytoestrogen found in a number of plants such as soybeans and there is accumulating evidence that it has beneficial effects on the regulation of glucose homeostasis. In this study we evaluated the effect of genistein on glucose homeostasis and its underlying mechanisms in normal and insulin-resistant conditions.

EXPERIMENTAL APPROACH

To induce insulin resistance, mice or differentiated 3T3-L1 adipocytes were treated with macrophage-derived conditioned medium. A glucose tolerance test was used to investigate the effect of genistein. Insulin signalling activation, glucose transporter-4 (GLUT4) translocation and AMP-activated PK (AMPK) activation were detected by Western blot analysis or elisa.

KEY RESULTS

Genistein impaired glucose tolerance and attenuated insulin sensitivity in normal mice by inhibiting the insulin-induced phosphorylation of insulin receptor substrate-1 (IRS1) at tyrosine residues, leading to inhibition of insulin-mediated GLUT4 translocation in adipocytes. Mac-CM, an inflammatory stimulus induced glucose intolerance accompanied by impaired insulin sensitivity; genistein reversed these changes by restoring the disturbed IRS1 function, leading to an improvement in GLUT4 translocation. In addition, genistein increased AMPK activity under both normal and inflammatory conditions; this was shown to contribute to the anti-inflammatory effect of genistein, which leads to an improvement in insulin signalling and the amelioration of insulin resistance.

CONCLUSION AND IMPLICATIONS

Genistein showed opposite effects on insulin sensitivity under normal and inflammatory conditions in adipose tissue and this action was derived from its negative or positive regulation of IRS1 function. Its up-regulation of AMPK activity contributes to the inhibition of inflammation implicated in insulin resistance.

Determinants of immediate extubation in the operating room after total thoracoscopic closure of congenital heart defects

OBJECTIVE

This study was designed to assess the factors that influence immediate extubation following totally thoracoscopic closure of congenital heart defects.

SUBJECTS AND METHODS

Clinical and operational data of 216 patients (87 males, average age 13.6 ± 10.9 years) were retrospectively analyzed. Atrial (ASD, n = 90) or ventricular septal defects (VSD, n = 126) were closed via a totally thoracoscopic approach. Ultra-fast-track anesthesia (UFTA) was used in all patients.

RESULTS

Immediate extubation in the operating room was successfully performed in 156 (72.2%) patients. A delayed extubation was completed in the intensive care unit in the remaining 60 (27.8%) patients. There was no significant difference in the age, sex, body weight, or type of congenital heart defect between the immediate and delayed extubation groups (p > 0.05). However, more patients in the delayed extubation group had severe preoperational pulmonary hypertension [8 (13.3%) vs. 4 (2.3%), p < 0.05]. The cardiopulmonary bypass time, aortic clamp time, and total duration of the surgery in the immediate extubation group were shorter than in the delayed extubation group (p < 0.05). Multivariate logistic regression analysis showed that preoperational pulmonary hypertension, duration of the surgery or cardiopulmonary bypass, and dosage of fentanyl used during the surgery were independent predictors for immediate extubation.

CONCLUSIONS

UFTA and immediate extubation in the operating room was feasible and safe in the majority of patients undergoing totally thoracoscopic closure of ASD or VSD. Preoperational pulmonary hypertension, duration of the surgery, and the dosage of fentanyl used for UFTA were the determining factors for immediate extubation.

A new caryolane sesquiterpene from Heteropappus altaicus (Willd.) Novopokr

A new caryolane sesquiterpene, 1β-methoxycaryol-9-one (1), along with eight known compounds (2-9), was isolated from the whole plant of Heteropappus altaicus. The structures were elucidated on the basis of comprehensive 1D- and 2D-NMR analysis and high-resolution mass spectrometry. The 13C-NMR data of compound 2 are reported for the first time.

Fracture resistance of root filled premolar teeth restored with direct composite resin with or without cusp coverage

AIM

To evaluate the fracture resistance and fracture patterns of root filled maxillary first premolar teeth (with mesio-occlusal cavity preparation) restored with several composite restoration designs.

METHODOLOGY

One hundred extracted sound human maxillary first premolars were randomly divided into five groups. Group 1 remained untreated (negative control). Conventional root canal treatment with additional mesial-occlusal cavity preparation was carried out on teeth in groups 2-5. In group 2, the teeth were restored intra-coronally with direct composite resin (positive control). In group 3, the palatal cusps of the teeth were reduced, and the cavities were restored with composite resin covering the palatal cusp (partial coverage). In group 4, the buccal and palatal cusps along with the distal marginal ridges were reduced; the cavities and cusps were restored with composite resin (conventional full coverage). In group 5, the buccal and palatal cusps were reduced but the distal marginal ridges were conserved. The cavities and the cusps were restored with composite resin (modified full coverage). All teeth were subjected to a progressive compressive loading parallel to their longitudinal axis until fracture. Fracture resistance was analysed using the one-way ANOVA and Fisher's LSD test. Fracture patterns were analyzed with chi-square test. The significance level was set at 0.05.

RESULTS

The fracture resistance (mean ± SD) of groups 1-5 was 1131 ± 207N, 904 ± 184N, 927 ± 224N, 1095 ± 289N and 1085 ± 243N, respectively (groups 1, 4, 5 > groups 2, 3; P = 0.004). Cusp fractures were recorded as the fracture pattern in 20 (100%), 19 (95%), 16 (80%), 8 (40%) and 12 (60%) premolars in groups 1-5, respectively (groups 1, 2 > groups 4, 5; group 3 > group 4; P < 0.001).

CONCLUSIONS

When direct composite resin was used to restore root filled maxillary first premolar teeth involving a proximal surface, those restored with full-coverage designs had greater fracture resistance.

A preliminary study of biological characteristics of Streptococcus oligofermentans in oral microecology

This study was designed to explore the biological characteristics of a new oral streptococcus species Streptococcus oligofermentans. Plaque samples were collected from caries-free and caries-active subjects. S. oligofermentans was selectively grown on Mitis salivarius agar plates and identified by using 2-step PCR and was isolated from 38% of 18 subjects. Isolates were found mostly on healthy tooth surfaces. S. oligofermentans had weaker abilities in acid production and demineralizing hydroxyapatite. When Streptococcus mutans was coincubated with S. oligofermentans, total number, acid production and calcium release were significantly inhibited. In conclusion, inhibition of S. mutans could be a beneficial biological characteristic of S. oligofermentans in oral microecology.

Survival of glass ionomer restorations placed in primary molars using atraumatic restorative treatment (ART) and conventional cavity preparations: 2-year results

OBJECTIVE

To compare the survival of glass ionomer cement (GIC) restorations placed in a dental clinic setting using both the atraumatic restorative treatment (ART) approach with hand instruments, and conventional cavity preparation with rotary instruments.

METHOD AND MATERIALS

Two encapsulated high-strength conventional GICs (Fuji IX GP, Ketac-Molar Aplicap) were placed in 82 Class I and 53 Class II preparations and one encapsulated non-gamma 2 amalgam alloy (GK-amalgam) was placed in 32 Class I preparations, in the primary molars of 60 Chinese children with a mean age of 7.40 +/- 1.24 (SD) years. Thus, 9 treatment groups were formed.

RESULTS

After two years, there were no significant survival differences found among 7 of the 9 treatment groups (p = 0.99). However, two groups comprising Fuji IX GP and Ketac-Molar Aplicap placed in Class II cavities prepared using the ART approach showed significantly lower restoration survivals (p < 0.001). Only 3 of the 72 initially sealed fissures adjacent to the restorations appeared to retain any GIC material.

CONCLUSIONS

In a clinic setting, both the ART hand instrument and conventional rotary instrument methods were equally suitable for high Class I restoration survival, but not for Class II restoration survival where the conventional cavity preparation method was preferable.

Non-mutans streptococci in patients receiving radiotherapy in the head and neck area

OBJECTIVE

To study mutans and non-mutans streptococci in patients after radiotherapy of the head and neck.

METHODS

Oral rinse samples collected from nasopharyngeal carcinoma patients before and after radiotherapy were diluted and cultured on nonselective and selective media for enumeration of total cultivable plaque flora, mutans and non-mutans streptococci and lactobacilli. Non-mutans streptococci were identified biochemically and by 16S rDNA sequence homology analysis.

RESULTS

After irradiation, mutans streptococci were not isolated; the levels of Streptococcus mitis and lactobacilli increased significantly. The level of Streptococcus salivarius increased, but the significance was the borderline. The level of Streptococcus sanguis decreased significantly after irradiation. The abundance of other oral streptococci species showed no significant changes.

CONCLUSIONS

S. mitis and S. salivarius are the predominant non-mutans streptococci in the high-caries-risk oral flora following radiotherapy.

Association of caries activity with the composition of dental plaque fluid

This study tests the hypothesis that caries activity is associated with lower degrees of saturation with respect to enamel mineral in dental plaque fluid following sucrose exposure. Plaque fluids were obtained from caries-free, caries-positive, and caries-active subjects. Samples were collected before and at 3 and 7 min after a sucrose rinse on consecutive weeks and analyzed for organic acids, inorganic ions, pH, calcium activity, and, in selected samples, total protein. After sucrose, pH values were significantly lower in the caries-active group in comparison with the caries-free and caries-positive groups. Total and free calcium concentrations increased with decreasing pH, with free calcium being about one-third of total calcium. The caries-active group exhibited significantly lower degrees of saturation with respect to enamel mineral, after sucrose, and had significantly higher mutans streptococci levels in plaque than did the caries-free samples. Thus, saturation levels in post-sucrose plaque fluids reflect the cariogenic potential of dental plaque.