Effect of cariogenic biofilm challenge on the surface hardness of direct restorative materials in situ

Objectives

The presence of cariogenic biofilm could result in surface degradation of composite and ionomeric restorative materials. Thus, this study evaluated in situ the alterations in the surface microhardness of these materials under biofilm accumulation and cariogenic challenge.

Methods

In a split-mouth, double-blind, cross-over study, 10 volunteers wore palatal intra-oral devices containing bovine enamel slabs restored with composite resin (CR – Z250) or resin-modified glass ionomer (RMGI – Vitremer). Two phases of 14 days were carried out, one for each restorative material. In one side of the device, biofilm was allowed to accumulate under a plastic mesh, whereas in the opposing side, regular brushing was carried out 3 times/day with a dentifrice containing 1100 μg F/g as NaF. A 20% sucrose solution was applied extra-orally 10×/day on each restored dental slab. Knoop microhardness was used to calculate the percentage of surface hardness loss (%SHL).

Results

All materials showed a decrease in surface hardness after the in situ period. The restorative materials presented the following average for %SHL: RMGI without biofilm accumulation = 8.9 and with biofilm accumulation = 25.6, CR without biofilm accumulation = 14.7 and with biofilm accumulation = 17.0.

Conclusion

Biofilm accumulation and the presence of cariogenic challenge promoted faster degradation of ionomeric materials, but this was not observed for composite resin.

Clinical significance

The oral environment affects the surface hardness of aesthetic restorative materials. Biofilm accumulation and cariogenic challenge promote surface degradation for ionomeric materials, but not for composite resin.     

Sucralose causes non-selective CD4 and CD8 lymphotoxicity via probable regulation of the MAPK8/APTX/EID1 genes: An in vitro/in silico study

One of the most widely used sweeteners in the world is sucralose. With sweetening power 600 times greater than sucrose, its use grows among those who seek to cut calories. Research shows that when heated, sucralose generates toxic products that attack the organism and interact with DNA. Our objective was to test this sweetener under unheated conditions and at average concentrations of consumption, evaluating parameters of cytotoxicity, genotoxicity, and immunotoxicity. For this purpose, we made use of lymphocyte cultures and the analysis of their CD3⁺, CD4⁺, and CD8⁺ subpopulations. In a complementary way, the mechanism of action is proposed here by computational methods. Our results showed that sucralose reduces non-selectively the total lymphocytes due to falls in the levels of the CD4⁺, CD8⁺, and CD4⁺CD8⁺ subpopulations. We observed an increase in the level of DNA damage and a gradual incidence of structural changes in the lymphocyte chromosomal sets. It was possible to propose that sucralose modulates the gene expression, interfering especially with the MAPK8, APTX, and EID1 genes. This article presents the results of an evidence-based approach to the safety of human health in the use of sucralose. Finally, this study points out that sucralose has cytotoxic, genotoxic, and mutagenic effects in the concentrations and conditions tested in human lymphocyte cell culture.     

Mycobacterium tuberculosis heat-shock protein 70 impairs maturation of dendritic cells from bone marrow precursors, induces interleukin-10 production and inhibits T-cell proliferation in vitro

In different inflammatory disease models, heat-shock proteins (hsp) and hsp-derived peptides have been demonstrated to possess anti-inflammatory properties. While some studies have shown that hsp can directly interact with antigen-presenting cells, others report that bacterial hsp can induce specific T cells with regulatory phenotypes. Effective characterization of the immunomodulatory effects of hsp 70, however, has historically been confounded by lipopolysaccharide (LPS) contamination. In this study, we compared the effects of LPS-free Mycobacterial tuberculosis hsp 70 (TBhsp70) and its possible contaminants on dendritic cells (DC). We demonstrate herein that LPS-free TBhsp70 inhibits murine DC maturation in vitro, while LPS-contaminated TBhsp70 induces DC maturation. Mock recombinant preparations have no effect. In contrast to LPS, TBhsp70 does not induce tumour necrosis factor-alpha production by DC, but interleukin-10. In vivo, only LPS-contaminated TBhsp70 induces up-regulation of CD86 in splenic mature DC. Finally, TBhsp70 inhibited phytohaemagglutinin-induced T-cell proliferation. Our results support the hypothesis that TBhsp70 does not have inflammatory potential, but rather has immunosuppressive properties.     

Subsyndromal depression: an impact on quality of life?

OBJECTIVE: The objective of this study was to demonstrate the association between quality of life and subsyndromal depression in a primary care clinic in a Brazilian sample. METHODS: This was a cross-sectional study. The cases were divided into three groups according to the severity of depressive symptoms: 1) subjects with major depressive disorder; 2) subjects with subsyndromal depression; 3) subjects without depressive symptoms--controls. The participants completed the World Health Organization Instrument to Assess Quality of Life (WHOQOL-BREF), the Quality of Life--Depression (QLDS), the Centers for Epidemiologic Studies--Depression instrument (CES-D), and the Composite International Diagnostic Interview (CIDI). RESULTS: The sample consisted of 438 primary care users (35.2% of them had subsyndromal depression). The subjects with major depression presented the worst impairment of quality of life, which was measured by the WHOQOL-BREF and the QLDS. The patients with subsyndromal depression had a smaller impact on their quality of life and the subjects without depression presented an even lower impact. The hierarchical linear regression involving demographic variables and the severity of depressive symptoms showed that the severity of depression was the variable with higher correlation with quality of life dimensions, presenting increased variation in the domains (from 9% to 24%). CONCLUSIONS: The results suggest that subsyndromal depression causes impairment of the quality of life in primary care patients of a Brazilian sample.     

Procedures performed by general practitioners and general internal medicine physicians - a comparison based on routine data from Northern Germany

Background

In response to a rising shortage of general practitioners (GPs), physicians in general internal medicine (GIM) have become part of the German primary care physician workforce. Previous studies have shown substantial differences in practice patterns between both specialties. The aim of this study was to analyse and compare the application of procedures by German GPs and GIM physicians based on routine data.

Methods

The Association of Statutory Health Insurance Physicians in the federal state Schleswig-Holstein (Northern Germany) provided invoicing data of the first quarters of 2013 and 2015. Differences between GPs and GIM physicians in the implementation rate of 46 selected primary care procedures were examined by means of the Pearson χ²-test. The selection of procedures was based on international and own preliminary studies on primary care procedures.

Results

In the first quarter of 2013/2015 respectively, 1228/1227 GPs and 447/484 GIM physicians provided services in Schleswig-Holstein. Significant differences were found for 20 of the 46 procedures. GPs had higher application rates of procedures concerning health screening (e.g. adolescent health examination, well-child visits) and minor surgery. GIM physicians more often applied technology-oriented procedures, such as ultrasound scans, electrocardiograms (ECG), and 24-h ambulatory blood pressure measurements. The treatment patterns of both specialities did not vary much during the study period. Cardiac stress testing was the only significantly increased GP procedure in that time.

Conclusions

Our results suggest substantial differences in the application of procedures between GPs and GIM physicians with potential consequences for the overall primary healthcare provision. The findings could foster a discussion about training needs for procedures in primary care to ensure its comprehensiveness. The results reflect scope for changes in vocational training in the future for an effective and efficient re-allocation of primary healthcare.

     

Impact of dietary fat on gut microbiota and low-grade systemic inflammation: mechanisms and clinical implications on obesity

Dietary fat strongly affects human health by modulating gut microbiota composition and low-grade systemic inflammation. High-fat diets have been implicated in reduced gut microbiota richness, increased Firmicutes to Bacteroidetes ratio, and several changes at family, genus and species levels. Saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA) and conjugated linolenic fatty acids share important pathways of immune system activation/inhibition with gut microbes, modulating obesogenic and proinflammatory profiles. Mechanisms that link dietary fat, gut microbiota and obesity are mediated by increased intestinal permeability, systemic endotoxemia, and the activity of the endocannabinoid system. Although the probiotic therapy could be a complementary strategy to improve gut microbiota composition, it did not show permanent effects to treat fat-induced dysbiosis. Based upon evidence to date, we believe that high-fat diets and SFA consumption should be avoided, and MUFA and omega-3 PUFA intake should be encouraged in order to regulate gut microbiota and inflammation, promoting body weight/fat control.