The ability of the Coincidence Doppler Broadening Spectroscopy to characterize polymers containing different chemical elements

Hydrocarbon polymers, O-containing, F-containing and Cl-containing polymers are comprehensively studied by Coincidence Doppler Broadening Spectroscopy (CDBS). It is shown that for polymers with different chemical structure, CDBS results can effectively distinguish polar groups CO, CCl, and CF. For polymers with similar chemical structure, the intensity of the element-specific peak in the CDBS ratio curve is dependent not only on the fraction of free positrons, but also on the content of characteristic atom in polymer repeated unit, and the polarity of the polymer molecule. For polymers containing several different polar groups, such as PCTFE (CF & CCl) and PFA (CF & CO), whether the element-specific peak appears or not depends on the amount of the polar groups and its positron capture ability. This work may provide insights into potential applications of CDBS for studying complex polymer systems.

[Research advances in nonalcoholic fatty liver disease and alcoholic liver disease in 2016]

Nonalcoholic fatty liver disease (NAFLD) has become the most important liver disease in the world and its prevalence rate still tends to increase. However, there are still no effective drugs so far. The complex and dynamic interactions between multiple effects/mediators in the pathophysiology of NAFLD provide new insights and help with stratification and redefinition of clinical phenotypes and evaluation of disease susceptibility and multiplicity of progression. They may also provide new targets for future treatment. Therefore, research on the pathophysiology of NAFLD is imperative. Alcoholic liver disease is a great harm to health and an important cause of end-stage liver disease. Some progress has been made in the research on alcoholic liver disease around the world in 2016. This article reviews the research advances in alcoholic liver disease in 2016 from the aspects of epidemiology, pathogenesis, diagnostic and therapeutic methods, and prognosis.

Minimum four-year subsequent surgery rates of cervical disc replacement versus fusion: A meta-analysis of prospective randomized clinical trials

INSTRUCTION

Anterior cervical discectomy and fusion (ACDF) is a well-accepted surgical management strategy for radiculopathy and/or myelopathy. However, complications sometimes required subsequent surgery at the operated and adjacent levels. Artificial cervical disc replacement (ACDR) has been accepted as the most extensive non-fusion procedure and is designed to preserve motion. However, some specific complications can result in subsequent surgery, thus, attracting the attention of investigators.

HYPOTHESIS

Compared with ACDF, ACDR had a lower subsequent surgery rates at both operated and adjacent levels after a minimum of four-years of follow-up.

MATERIAL AND METHODS

A meta-analysis was performed with articles published prior to February 2016. Only randomized controlled trials that reported a minimum of 4 years of follow-up with regard to the rates of subsequent surgeries after ACDR compared with ACDF were included in this study. Two reviewers independently screened the articles and data following the PRISMA statement.

RESULTS

Our data showed that the pooled overall rate of subsequent surgery at the operated level and adjacent levels was lower in the ACDR group (7.4%) than in the ACDF group (16.8%) (P=0.0006). For subsequent surgery at the operated level, patients who received ACDR had a lower rate of subsequent surgery than patients who received ACDF (P<0.0001). With respect to the adjacent level, ACDR also had fewer subsequent surgeries compared with ACDF (P<0.0001).

CONCLUSION

ACDR had significantly fewer subsequent surgical interventions compared with ACDF, However, a review of the literature showed that there were an insufficient number of studies with respect to subsequent surgery with a minimum of 4 years of follow-up. Hence, longer-term, multicenter studies are needed for better evaluation of the rate of subsequent surgery after ACDR.

LEVEL OF EVIDENCE

Level I, meta-analysis of high-powered prospective randomized trials.

[Body mass index, waist circumference and waist-to-height ratio associated with the incidence of type 2 diabetes mellitus: a cohort study]

OBJECTIVE

To investigate the association between body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), and the incidence risk of type 2 diabetes mellitus (T2DM).

METHODS

In total, 20 194 participants ≥18 years old were selected randomly by cluster sampling from two township (town) of the county in Henan province from July to August of 2007 and July to August of 2008 and the investigation included questionnaires, anthropometric measurements, fasting plasma glucose, and lipid profile examination were performed at baseline; 17 236 participants were enrolled in this cohort study. 14 720 (85.4%) were followed up from July to August 2013 and July to October 2014. Finally, 11 643 participants (4 301 males and 7 342 females) were included in this study. Incidence density and Cox proportional hazards regression models were used to evaluate the risk of T2DM associated with baseline BMI, WC, WHtR, and their dynamic changes.

RESULTS

After average of 6.01 years following up for 11 643 participants, 613 developed T2DM and the incidence density was 0.89 per 100 person-years. After adjusted for baseline sex, age, smoking, drinking, family history of diabetes, as well as the difference of fasting plasma-glucose (FPG), total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), systolic blood pressure (SBP), diastolic blood pressure (DBP) between baseline and follow-up, Cox Proportional-Hazards regression analysis indicated that T2DM risk of baseline BMI overweight group, BMI obesity group, abnormal WC group and abnormal WHtR group were significantly higher than that of the corresponding baseline normal groups , and the incidence risk of T2DM reached the highest for those whose baseline BMI, WC and WHtR were all abnormal, the corresponding HR (95%CI) were 2.05 (1.62-2.59), 3.01 (2.33-3.90), 2.34 (1.89-2.90), 2.88 (2.21-3.74), 3.32 (2.50-4.40), respectively. Whether baseline BMI/WC was normal or not, T2DM risk increased if baseline WHtR was abnormal, and the HR (95%CI) of baseline normal BMI/abnormal WHtR group, baseline abnormal BMI/abnormal WHtR group, baseline normal WC/abnormal WHtR group, baseline abnormal WC/abnormal WHtR group were 1.88 (1.29-2.74), 3.08 (2.34-4.05), 2.15(1.53-3.00), 3.22 (2.45-4.23), respectively. The analysis for dynamic changes of BMI, WC, and WHtR indicated that in baseline normal WC or WHtR group, T2DM risk increased when baseline normal WC or WHtR developed abnormal at follow-up, and the corresponding HR (95%CI) were 1.79 (1.26-2.55), 2.12(1.32-3.39), respectively. In baseline abnormal WC or WHtR group, T2DM risk decresed when baseline abnormal WC or WHtR reversed to normal at follow-up, and the corresponding HR (95%CI) were 2.16 (1.42-3.29), 2.62 (1.63-4.20), respectively.

CONCLUSION

BMI, WC, and WHtR were associated with increased T2DM risk. The more abnormal aggregation of BMI, WC, and WHtR presents, the higher T2DM risk was. T2DM risk could be decreased when abnormal WC or WHtR reversed to normal.

[Efficacy of antiretroviral therapy and influencing factors for people living with HIV/AIDS in designated hospitals in Harbin]

OBJECTIVE

To understand the efficacy of antiretroviral therapy for people living with HIV/AIDS and influencing factors; and provide evidence to improve the treatment of HIV infection and AIDS for the better life of the patients.

METHODS

A cross sectional study was conducted in designated AIDS hospitals in Harbin. A questionnaire was used to collect the information of the patients receiving treatment in these hospitals. The statistical analysis was done with software SAS 9.2 and Excel 2010. Univariate analysis was performed with t test and multivariate analysis was performed with ordinal logistic regression model. Wilcoxon ranks sum test was conducted to compare the CD4(+) T lymphocyte counts.

RESULTS

The number of the patients receiving antiretroviral therapy was in increase in recent years. The HIV infection route was mainly homosexual contact. The CD4(+)T lymphocyte count of the patients increased at different levels after ≥6 months treatment(P<0.01). Household income(P<0.05), adherence to treatment plan or not(P<0.05), social relationship(P< 0.05), concern of economic cost(P<0.01)medication compliance(P<0.01)and initial level of CD4(+) T lymphocyte(P<0.01)were the influencing factors for antiretroviral therapy efficacy.

CONCLUSION

In designated hospitals in Harbin, the number of the patients receiving HIV antiretroviral therapy kept to increase and the efficacy of the treatment was obvious.

[Influences of genetic and environmental factors on smoking related behaviors among male twin adults in China]

OBJECTIVE

To analyze the influences of genetic and environmental factors on smoking behavior, smoking cessation and onset age of smoking less than 20 years in male twin adults.

METHODS

A face-to-face questionnaire was conducted to collect data from 6 458 pair male twins aged ≥25 years registered in 9 provinces(municipality)in China. The heritability of three smoking related behaviors were calculated by using structural equation models.

RESULTS

The ACE models were the best models of the three dimensions of smoking, i.e. smoking behavior, smoking cessation and onset age of smoking less than 20 years for male twins, and the corresponding heritability of these behaviors were 0.26(0.19-0.34), 0.27(0.19-0.37)and 0.05(0.00-0.14), respectively. When adjusted for area and age, the heritability of these three behaviors were 0.26(0.19-0.34), 0.31(0.00-0.74)and 0.05(0.00-0.14), respectively.

CONCLUSIONS

All the three smoking related behaviors were affected by genetic factors, but environment factors had more effect on them. For smoking cessation, the heritability was highest, but the influence of environmental factors was lowest. Meanwhile, for onset age of smoking, the influence of environmental factors was highest.

[Establishing a noninvasive prediction model for type 2 diabetes mellitus based on a rural Chinese population]

OBJECTIVE

To provide a noninvasive type 2 diabetes mellitus (T2DM) prediction model for a rural Chinese population.

METHODS

From July to August, 2007 and July to August, 2008, a total of 20 194 participants aged ≥18 years were selected by cluster sampling technique from a rural population in two townships of Henan province, China. Data were collected by questionnaire interview, anthropometric measurement, and fasting plasma glucose and lipid profile examination. A total 17 265 participants were followed up from July to August, 2013 and July to October, 2014. Finally, 12 285 participants were selected for analysis. Data for these participants were randomly divided into a derivation group (derivation dataset, n= 6 143) and validation group (validation dataset, n=6 142) by 1∶1, respectively. Randomization was carried out by the use of computer-generated random numbers. A Cox regression model was used to analyze risk factors of T2DM in the derivation dataset. A T2DM prediction model was established by multiplying β by 10 for each significant variable. After the total score was calculated by the model, analysis of the receiver operating characteristic (ROC) curve was performed. The area under the ROC curve (AUC) was used for evaluating model predictability. Furthermore, the model's predictability was validated in the validation dataset and compared with the Finnish Diabetes Risk Score (FINDRISC) model.

RESULTS

A total 779 of 12 285 participants developed T2DM during the 6-year study period. The incidence rate was 6.12% in the derivation dataset (n=376) and 6.56% in the validation dataset (n=403). The difference was not statistically significant (χ(2)=1.00, P=0.316). A total of four noninvasive T2DM prediction models were established using the Cox regression model. The ROCs of the risk score calculated by the prediction models indicated that the AUCs of these models were similar (0.67-0.70). The AUC and Youden index of model 4 was the highest. The optimal cut-off value, sensitivity, specificity, and Youden index were scores of 25, 65.96%, 66.47%, and 0.32, respectively. Age, sleep time, BMI, waist circumference, and hypertension were selected as predictive variables. Using age<30 years as reference, β values were 1.07, 1.58, and 1.67 and assigned scores were 11, 16, and 17 for age groups 30-44, 45-59, and ≥60 years, respectively. Using sleep time<8.0 h/d as reference, the β value and assigned score were 0.27 and 3, respectively, for sleep time ≥10.0 h/d. Using BMI 18.5-23.9 kg/m(2) as reference, β values were 0.53 and 1.00 and assigned scores 5 and 10, respectively, for BMI 24.0-27.9 kg/m(2), and ≥28.0 kg/m(2). Using waist circumference <85 cm for males/< 80 cm for females as reference, β values were 0.44 and 0.65 and assigned scores 4 and 7, respectively, for 85 cm ≤ waist circumference <90 cm for males/80 cm≤ waist circumference <85 cm for females, and waist circumference ≥90 cm for males/≥85 cm for females. Using nonhypertension as reference, the respective β value and assigned score were 0.34 and 3 for hypertension. The AUC performance of this model and the FINDRISC model was 0.66 and 0.64 (P=0.135), respectively, in the validation dataset.

CONCLUSION

Based on this cohort study, a noninvasive prediction model that included age, sleep time, BMI, waist circumference, and hypertension was established, which is equivalent to the FINDRISC model and applicable to a rural Chinese population.

Functional Advantages of Porphyromonas gingivalis Vesicles

Porphyromonas gingivalis is a keystone pathogen of periodontitis. Outer membrane vesicles (OMVs) have been considered as both offense and defense components of this bacterium. Previous studies indicated that like their originating cells, P. gingivalis vesicles, are able to invade oral epithelial cells and gingival fibroblasts, in order to promote aggregation of some specific oral bacteria and to induce host immune responses. In the present study, we investigated the invasive efficiency of P. gingivalis OMVs and compared results with that of the originating cells. Results revealed that 70-90% of human primary oral epithelial cells, gingival fibroblasts, and human umbilical vein endothelial cells carried vesicles from P. gingivalis 33277 after being exposed to the vesicles for 1 h, while 20-50% of the host cells had internalized P. gingivalis cells. We also detected vesicle-associated DNA and RNA and a vesicle-mediated horizontal gene transfer in P. gingivalis strains, which represents a novel mechanism for gene transfer between P. gingivalis strains. Moreover, purified vesicles of P. gingivalis appear to have a negative impact on biofilm formation and the maintenance of Streptococcus gordonii. Our results suggest that vesicles are likely the best offence weapon of P. gingivalis for bacterial survival in the oral cavity and for induction of periodontitis.

Visible and near-infrared imaging spectrometer and its preliminary results from the Chang'E 3 project

In order to conduct lunar surface mineral composition studies and content analysis, the Visible and Near-infrared Imaging Spectrometer (VNIS), one of the scientific payloads of the Chang'E 3 Yutu rover, has been developed to detect lunar surface objects and to obtain their reflectance spectra and geometric images. This is achieved with a 45° visual angle and at a height of 0.69 m. VNIS is equipped with a lunar surface calibration function, and the spectral range is 0.45-2.40 μm with a spectral resolution of 2-12 nm. It is capable of synchronously acquiring the full spectrum of lunar surface objects and in situ calibration. Here, we describe the VNIS and explain the preliminary results of the lunar surface exploration and calibration, which provides valuable information for scientific data processing and applications.

Genetic diversity in the oral pathogen Porphyromonas gingivalis: molecular mechanisms and biological consequences

Porphyromonas gingivalis is a Gram-negative anaerobic bacterium that colonizes the human oral cavity. It is implicated in the development of periodontitis, a chronic periodontal disease affecting half of the adult population in the USA. To survive in the oral cavity, these bacteria must colonize dental plaque biofilms in competition with other bacterial species. Long-term survival requires P. gingivalis to evade host immune responses, while simultaneously adapting to the changing physiology of the host and to alterations in the plaque biofilm. In reflection of this highly variable niche, P. gingivalis is a genetically diverse species and in this review the authors summarize genetic diversity as it relates to pathogenicity in P. gingivalis. Recent studies revealing a variety of mechanisms by which adaptive changes in genetic content can occur are also reviewed. Understanding the genetic plasticity of P. gingivalis will provide a better framework for understanding the host-microbe interactions associated with periodontal disease.

Molecular characterization of the pseudorabies virus UL2 gene

A 948-bp sequence of the UL2 gene was amplified from the pseudorabies virus (PRV) Becker strain genome using polymerase chain reaction, and the gene identity was confirmed through further cloning and sequencing. Bioinformatic analysis indicated that the PRV UL2 gene encodes a putative polypeptide with 315-amino acid residues. Its encoding protein, designated UL2, has a conserved uracil-DNA glycosylase (UDG)_F1 domain, which is closely related to the herpesvirus UDG family and is highly conserved among its counterparts encoded by UDG genes. Multiple nucleic acid and amino acid sequence alignments suggested that the product of PRV UL2 has a relatively higher homology with UL2-like proteins of Alphaherpesvirinae than that of other subfamilies of Herpesviridae. In addition, phylogenetic analysis showed that PRV UL2 had a close evolutionary relationship with members of Alphaherpesvirinae, especially members of the genus Varicellovirus of bovine herpesvirus 1 and bovine herpesvirus 5. Antigen prediction indicated the presence of several potential B-cell epitopes in PRV UL2. In addition, secondary structure and 3-dimensional structure prediction revealed that PRV UL2 consisted predominantly of an α-helix. Taken together, these results provide molecular biological insight for the further study of the function and mechanism of UL2 during PRV infection.

Bacterial sex in dental plaque

Genes are transferred between bacteria in dental plaque by transduction, conjugation, and transformation. Membrane vesicles can also provide a mechanism for horizontal gene transfer. DNA transfer is considered bacterial sex, but the transfer is not parallel to processes that we associate with sex in higher organisms. Several examples of bacterial gene transfer in the oral cavity are given in this review. How frequently this occurs in dental plaque is not clear, but evidence suggests that it affects a number of the major genera present. It has been estimated that new sequences in genomes established through horizontal gene transfer can constitute up to 30% of bacterial genomes. Gene transfer can be both inter- and intrageneric, and it can also affect transient organisms. The transferred DNA can be integrated or recombined in the recipient's chromosome or remain as an extrachromosomal inheritable element. This can make dental plaque a reservoir for antimicrobial resistance genes. The ability to transfer DNA is important for bacteria, making them better adapted to the harsh environment of the human mouth, and promoting their survival, virulence, and pathogenicity.

Preparation and characterization of an antiserum against truncated UL54 protein of pseudorabies virus

Pseudorabies virus (PRV) early protein UL54 is a homolog of herpes simplex virus 1 immediate-early protein ICP27, which is a multifunctional protein essential for the virus replication. However, the precise role of the PRV UL54 protein in the virus life cycle is still poorly understood. To shed more light on this problem, we considered it essential to have available an antiserum specifically detecting this protein. Since it was known that a full-length UL54 protein is a too big molecule for efficient expression in prokaryotic systems, it was truncated from 1 to 66 N-terminal amino acids, fused to EYFP-His tag and expressed in Escherichia coli through an appropriate expression vector. The truncated protein was purified by Ni-NTA affinity chromatography and used for raising an antiserum in rabbits. Western blot analysis showed that this antiserum specifically recognized the purified truncated as well as full-length UL54 protein in PRV-infected cells. Immunofluorescence assay confirmed the latter finding and also demonstrated localization of this protein first in nucleoli and later in whole nuclei of PRV-infected cells. These results indicate that the prepared antiserum could serve as a valuable tool in further studies of PRV UL54 protein function.

Phenotypic characterization of mononuclear inflammatory cells following equine hydroxyapatite/collagen block grafting in rats

To measure the inflammatory changes associated with the implantation of an equine hydroxyapatite and collagen-containing block graft (eHAC block) in a rodent model system, an eHAC block graft was implanted subcutaneously in rats. Control groups included saline, turpentine oil, and human mineralized particulate allograft (hMPA). Animals were sacrificed and tissue samples obtained after three days, as well as after 1, 2, 4 and 8 weeks. A panel of immunologic probes was used to identify circulatory monocytic cells (ED1), resident mononuclear phagocytes (ED2), mononuclear phagocytes of lymphoid origin (ED3), expression of Ia antigen (OX6), T-cells (OX19), and B-cells (OX33). Immunocytochemical localization was performed and mononuclear cells localized with each immunologic probe counted. Rat sera obtained after eight weeks were used for nitrocellulose dot-blotting to assess circulating anti-equine immunoglobulins. Statistical analysis was performed using two-way analysis of variance, in conjunction with the Bonferroni correction to account for multiple comparisons. A transient increase in monocytes at 3 days and 1 week was observed in all groups, but was significantly higher in the turpentine control (P < 0.0001). A significant increase in the numbers of mononuclear cells detected with clones ED2 and ED3 was observed in specimens from the turpentine group, in contrast to the other groups in the 3 day to 4 week interval (P < 0.0001), as well as within all time periods (P < 0.0001). A statistically significant difference in numbers of ED3-positive cells was observed in the hMPA group compared to the saline and the eHAC block groups after one week (P < 0.0001). Significantly more OX6-positive cells were observed in the turpentine group, compared to other groups (3 days to 1 week; P < 0.0001). T-lymphocytes were essentially absent except for rats given turpentine (after 1 week). No B-lymphocyte response was found and none of the rats developed systemic anti-equine antibodies. These data indicate that a cellular immune response is not elicited following implantation with the eHAC block graft, which might serve as an alternative material for regenerative therapy.

A novel formulation effective in killing oral biofilm bacteria

OBJECTIVE

To determine if a novel formulation is effective in killing oral biofilm streptococci in vitro and in vivo.

METHODS

Efficacy of 0.5% levulinic acid and 0.05% sodium dodecyl sulfate (SDS) in killing Streptococcus gordonii CH1, Streptococcus gordonii DL1, Streptococcus mitis NCTC10712, Streptococcus oralis KS32AR, Streptococcus mutans BM71, and Streptococcus mutans GS5 in their biofilm form was measured in vitro, using microtiter plates and subsequent counts on Mitis-Salivarius agar plates. The safety and efficacy in vivo were evaluated using a mouse model.

RESULTS

Our anti-microbial formulation completely eliminated all the biofilm streptococcal species tested within 30 seconds (a reduction of 10(7) CFU/ml), whereas the positive control Listerine only demonstrated moderate reduction in vitro. Application of the formulation twice a day for 7 days in the murine oral cavity resulted in significantly more reduction of established S. gordonii DL1 oral biofilm bacteria than Listerine. The formulation did not cause any adverse effect in the murine oral cavity within a 2-week period.

CONCLUSIONS

We have demonstrated that the novel mouth rinse exhibits high efficacy in killing oral bacteria in their biofilm forms, results in no adverse effect in vivo, and contains alcohol-free components.

The effects of thyroid hormone abnormalities on periodontal disease status

Thyroid hormones play an important role in the regulation of physiologic processes. Thyroid disease can lead to imbalance in the homeostasis of the body and affect the healing capacity of tissues. However, limited data are available regarding the relationship between thyroid hormone imbalance (thyroid disease) and periodontal health. This review is carried out to summarize the relationship between thyroid disease and periodontal status. PUBMED and MEDLINE searches of both human and animal studies were performed to investigate the relationship between thyroid disease, periodontal status, and dental implants. Results suggest that thyroid diseases may affect the status of periodontal diseases, especially in hypothyroid conditions. The duration from disease onset to treatment of thyroid disorders may be critical, since uncontrolled thyroid disease may result in destruction of the periodontium. Further controlled studies are needed to explore the relationship between thyroid hormone imbalance and periodontal status. Periodontal therapies, including dental implant placement, appear to be safe with no increase in treatment failure, so long as the status of the thyroid gland is controlled.

The whole is greater than the sum of its parts: dental plaque bacterial interactions can affect the virulence properties of cariogenic Streptococcus mutans

It has been well established that dental caries results from the accumulation of dental plaque on tooth surfaces. Several decades of in vitro and as well as clinical studies have identified Streptococcus mutans as an important etiological agent in carious lesion formation. In addition, a variety of approaches have suggested that interactions between the bacterial components of biofilms can influence the properties of such polymicrobial structures. Therefore, it is likely that the mere presence of S. mutans in dental plaque does not alone account for the cariogenic potential of such biofilms. Recent studies have indicated that several bacteria commonly found in dental plaque can influence either the viability and/or virulence properties of S. mutans. This review will summarize some of the more recent findings in this regard as well as their implications for the development of novel anti-caries strategies.

High resolution characterization of modifications in fused silica after exposure to low fluence 355 nm laser at different repetition frequencies

We report on the characterization of modifications in fused silica after exposure to low fluence (2 J/cm2) 355 nm laser at repetition frequencies of 1 Hz, 5 Hz and 10 Hz. Synchrotron based XRF spectroscopy is employed to study concentration variation of metal inclusions in the surface layer. Positron annihilation lifetime spectroscopy is used to probe atomic size defects variation in bulk silica. FT-IR is used to characterize changes of bond length and angle of Si-O-Si covalent bond of irradiated silica. Compared to the basic frequency, the big loss of cerium and iron concentration, the size enlargement of vacancy cluster and the decrease of Si-O-Si covalent bond length after 10 Hz laser irradiation are illustrated by our data. These tiny modifications provide important data to investigate laser damage mechanism.

Therapeutic effect of statin on aortic stenosis: a review with meta-analysis

BACKGROUND

Aortic stenosis (AS) is a common progressive disease. Statins have been hypothesized to delay its progression via pleiotropic mechanisms. However, results of clinical trials focusing on statin therapy in AS patients have been controversial.

OBJECTIVE

To analyse and summarize the findings in recent statin trials and to discuss the rationale of statin usage in AS populations.

METHODS

A comprehensive database search was conducted by two independent reviewers. Controlled trials that compared progression of AS between statin and non-statin therapy published before 31 December 2008 were included. Data were extracted for meta-analysis, to estimate overall effects, if available. Factors that contributed to heterogeneities among the trials were analysed.

RESULTS

The meta-analysis included nine trials with a total of 2947 patients. Statin therapy displayed an overall statistically significant effect on delaying AS progression. The weighted mean difference (statin vs. control) of annual increase of peak aortic-jet velocity was -0·12 m/s (95% confidence interval -0·22 to -0·03); the increase of mean transaortic pressure gradient was -1·64 mmHg per year (-3·27 to -0·01); Heterogeneity-analysis suggested that the baseline risk factors and characteristics of the patients, the use of different statins, and the time point to initiate statin therapy, may be important considerations when interpreting the result of individual studies.

CONCLUSION

Although the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) trial reported negative results in delaying AS progression in low-risk patients, the potential benefits of statins in those with multiple risk factors and their value in preventing future coronary events call for further investigation of different categories of AS patients.

Periodontal pathogens interfere with quorum-sensing-dependent virulence properties in Streptococcus mutans

BACKGROUND AND OBJECTIVE

The mechanism by which periodontal pathogens dominate at disease sites is not yet understood. One possibility is that these late colonizers antagonize the quorum-sensing systems of early colonizers and render those early colonizers less resistant to environmental factors. In this study, we utilized Streptococcus mutans, a well-documented oral Streptococcus with many quorum-sensing-dependent properties, as an example of an earlier colonizer antagonized by periodontal pathogens.

MATERIAL AND METHODS

In this study, S. mutans NG8 and S. mutans LT11 were used in experiments assessing transformation, and S. mutans BM71 was used in experiments investigating bacteriocin production. The effects of the periodontal pathogens Porphyromonas gingivalis and Treponema denticola on these competence-stimulating peptide-dependent properties were evaluated in mixed-broth assays.

RESULTS

Both P. gingivalis (either live bacteria or membrane vesicles) and T. denticola antagonized transformation in S. mutans NG8 and LT11. The production of bacteriocin by S. mutans BM71 was also inhibited by P. gingivalis and T. denticola. Boiling of these late colonizers before addition to the broth cultures abolished their ability to inhibit S. mutans transformation and bacteriocin production. P. gingivalis and T. denticola inactivated S. mutans exogenous competence-stimulating peptide, whereas the boiled bacteria did not.

CONCLUSIONS

This study demonstrated that periodontal pathogens antagonize S. mutans quorum-sensing properties. This may render S. mutans less virulent and less resistant to environmental antibacterial factors.

Influence of bisphosphonates on alveolar bone loss around osseointegrated implants

The relationship between bisphosphonates (BP) and dental implant failure has not been fully elucidated. The purpose of this retrospective radiographic study was to examine whether patients who take BP are at greater risk of implant failure than patients not using those agents. Treatment records of 362 consecutively treated patients receiving endosseous dental implants were reviewed. The patient population consisted of 227 women and 135 men with a mean age of 56 years (range: 17-87 years), treated in the University at Buffalo Postgraduate Clinic from 1997-2008. Demographic information collected included age, gender, smoking status, as well as systemic conditions and medication use. Implant characteristics reviewed included system, date of placement, date of follow-up radiographs, surgical complications, number of exposed threads, and implant failure. The relationship between BP and implant failure was analyzed using generalized estimating equation (GEE) analysis. Twenty-six patients using BP received a total of 51 dental implants. Three implants failed, yielding success rates of 94.11% and 88.46% for the implant-based and subject-based analyses, respectively. Using the GEE statistical method we found a statistically significant (P  =  .001; OR  =  3.25) association between the use of BP and implant thread exposure. None of the other variables studied were statistically associated with implant failure or thread exposure. In conclusion, patients taking BP may be at higher risk for implant thread exposure.

Ferromagnetism in dilute magnetic semiconductors through defect engineering: Li-doped ZnO

We demonstrate, both theoretically and experimentally, that cation vacancy can be the origin of ferromagnetism in intrinsic dilute magnetic semiconductors. The vacancies can be controlled to tune the ferromagnetism. Using Li-doped ZnO as an example, we found that while Li itself is nonmagnetic, it generates holes in ZnO, and its presence reduces the formation energy of Zn vacancy, and thereby stabilizes the zinc vacancy. Room temperature ferromagnetism with p type conduction was observed in pulsed laser deposited ZnO:Li films with certain doping concentration and oxygen partial pressure.

New class of plastic bulk metallic glass

An intrinsic plastic Cu(45)Zr(46)Al(7)Ti(2) bulk metallic glass (BMG) with high strength and superior compressive plastic strain of up to 32.5% was successfully fabricated by copper mold casting. The superior compressive plastic strain was attributed to a large amount of randomly distributed free volume induced by Ti minor alloying, which results in extensive shear band formation, branching, interaction and self-healing of minor cracks. The mechanism of plasticity presented here suggests that the creation of a large amount of free volume in BMGs by minor alloying or other methods might be a promising new way to enhance the plasticity of BMGs.

Identification of a signalling molecule involved in bacterial intergeneric communication

The development of complex multispecies communities such as biofilms is controlled by interbacterial communication systems. We have previously reported an intergeneric communication between two oral bacteria, Streptococcus cristatus and Porphyromonas gingivalis, that results in inhibition of fimA expression. Here, we demonstrate that a surface protein, arginine deiminase (ArcA), of S. cristatus serves as a signal that initiates intergeneric communication. An ArcA-deficient mutant of S. cristatus is unable to communicate with P. gingivalis. Furthermore, arginase activity is not essential for the communication, and ArcA retains the ability to repress expression of fimA in the presence of arginine deiminase inhibitors. These results present a novel mechanism by which intergeneric communication in dental biofilms is accomplished.

[Effects of fertilizing levels on output and quality of Pinellia ternate]

OBJECTIVE

To compare the effects of the different fertilizing levels on the output, the effective element, the content of heavy-metal, the grade and the ratio of wet to dry of Pinella ternate to obtain the best fertilize ratio on the planting.

METHODS

The orthogonal desing method L9 (3(4)) was applied on the comparison between the different fertilization levels. The content of alkaloid was determined by UV spectrophotometer. The content of heavy-metal was determined by atom absorption.

RESULTS

The factors that affected the output and the quality of Pinellia ternate were N > P > K.

CONCLUSION

The best fertilizer combination is N 25 g/m2 ,P2O5 18 g/m2, K2O9 g/m2 and the application ratio is 2. 8: 2: 1 for them, in which the higher output and the content of alkaloid should be obtained.