Influence of the restorative procedure factors on stress values in premolar with MOD cavity: a finite element study

In order to investigate the influence of cusp reduction, cavity isthmus width, and restorative material on stress values in premolar with mesio-occlusal-distal (MOD) cavity, numerical simulations were done on three-dimensional (3D) models of a maxillary second premolar designed using computerized tomography (CT) scan images. The use of four restorative materials (direct resin composite, direct resin composite with resin-modified glass-ionomer cement as the base, indirect resin composite, ceramic), three cavity preparation designs (without cusp coverage, 2-mm palatal cusp coverage, 2-mm palatal and buccal cusp coverage), and two cavity isthmus widths (1/2 and 2/3 intercuspal width) were simulated. After applying a static load of 200 N on the occlusal surface of the tooth, von Mises stresses in the enamel, dentin, and restoration were calculated using finite element analysis (FEA). Stress values in the enamel were primarily influenced by cavity preparation design, while restorative material showed higher contribution in dentin. The lowest stress values were obtained in models with cusp coverage and indirect restorations. Cavity isthmus width had minimal influence on stress values in tooth structures. None of the investigated factors determined stress values in the restoration. In conclusion, the use of ceramic restoration covering both palatal and buccal cusp provided the most favourable stress distribution of premolars with MOD cavity.

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Genome-wide linkage scans for prediabetes phenotypes in response to 20 weeks of endurance exercise training in non-diabetic whites and blacks: the HERITAGE Family Study

Aims/hypothesis Impaired insulin secretion, insulin action, insulin-independent glucose effectiveness, glucose tolerance and the associated abnormalities in insulin and glucose metabolism phenotypes are precursors of type 2 diabetes. Genome-wide multipoint variance component linkage scans were carried out using 654 markers to identify quantitative trait loci for insulin sensitivity, acute insulin response to glucose, disposition index and glucose effectiveness training responses in whites and blacks in the HERITAGE Family Study.Methods These phenotypes were obtained from an IVGTT with the minimal model. The distributions of insulin sensitivity, acute insulin response to glucose and disposition index training responses (post-training minus baseline) were approximately normalised using a square-root transformation. All phenotypes were adjusted for the effects of age, BMI and their respective baseline values within sex and generation by race prior to linkage scans.Results In blacks, a promising linkage with a maximum lod score of 3.1 on 19q (54–62 Mb) for glucose effectiveness training response was found. Six interesting linkages with lod scores of at least 1.0 were found for disposition index training response in whites. They included 1p (30 Mb), 3q (152 Mb), 6p (23–42 Mb), 7q (95–96 Mb), 10p (15 Mb) and 12q (119–126 Mb).Conclusions/interpretation Quantitative trait loci for 20 weeks of endurance exercise training responses in insulin action and glucose metabolism phenotypes were found on chromosome 19q as well as 6p and 7q, with nominal (6p, 7q) but consistent (6p) linkages across the races.     

Patterns of internet use and mental health of high school students in Istria County,Croatia: cross-sectional study

Aim

To examine associations between different forms of internet use and a number of psychological variables related to mental health in adolescents.

Methods

A cross-sectional survey was carried out on a representative sample of students (N = 1539) from all high schools in the region of Istria in Croatia (14-19 years). The associations between four factors of internet use and nine mental health indicators were analyzed using canonical correlation analysis.

Results

The four canonical functions suggested a significant association between different types of internet use and specific indicators of mental health (P < 0.001). Problematic internet use, more typical among boys, was associated with general aggressive behavior and substance abuse (P < 0.001). Experiences of harassment, more typical among girls, were associated with health complaints, symptoms of depression, loneliness, and fear of negative evaluation (P < 0.001). Using the internet for communication and entertainment was associated with better relationships with peers (P < 0.001), while use of the internet for academic purposes was associated with conscientiousness (P < 0.001).

Conclusion

The results suggest that different patterns of internet use are significantly associated with specific sets of positive and negative mental health indicators. The data support the assumption that internet use can have both positive and adverse effects on the mental health of youth.New technologies, and especially the use of computers and the internet, are part of the everyday lives of young people and have a significant impact on their psychological development. Indeed, this mass use of new media technologies presents parents and society with a challenge to protect and support the positive development of children and youth. To date, a number of studies have examined the positive and negative aspects of using internet technologies.Literature points to several positive aspects of internet use (1,2): for information acquiring, communication, and social networking, entertainment, and online shopping. More specifically, adolescents use the internet as a useful source of information about school assignments, daily events, interests and hobbies, or health and sexuality concerns. In these instances, online activities aimed at connecting with peers have a significant place. Visiting social networking sites and using communication tools such as email, chat, forums, and discussion groups enables the creation of friendships and social groups and contributes to the development of personal identity (3). The use of computers and the internet (cyberspace) has also been argued to provide opportunities for new and faster learning, exercising one''s self-control, considering different opinions, expressing one''s attitudes and tolerance, and developing skills in critical thinking and decision-making (4). Best et al (5) found that use of online communication technologies contributed to increased self-confidence, better perception of social support, greater social capital, positive experimenting with one’s own identity, and greater opportunities for open self-disclosure. Conversely, adolescents who do not use the internet might trail behind in the development of such positive attitudes and traits and risk being rejected by their peers (6). Finally, Livingstone et al (7) found that a certain amount of risk exposure was useful in building resilience.In contrast to these positive influences of internet use, harmful effects of internet abuse range from exposure to inappropriate sexual content, pornography, and violence (2,7) to humiliation and cyber-bullying (6,8-10) and internet addiction (11,12). Research has confirmed the link between internet abuse and social isolation, depression and, anxiety (1,5,13,14), alcohol and drug abuse and gambling (15), and problems with physical health (16). Ybarra and Mitchell (17) found a connection between experiences of threats or humiliation in the virtual world and absences from school, lower school achievement, substance use disorders, delinquency and depression. Fekkes et al (18) point to the association between victimizing experiences and a number of physical, emotional, and behavioral problems, such as headaches, tension, fatigue, loss of appetite, enuresis, and sleeping problems. Slonje and Smith (19) define such experiences as a product of cyber-bullying and argue that this can be viewed as another form of aggressive behavior. Gender has emerged as a significant predictor of the manner in which the internet is used. Specifically, girls tend to experience victimizing experiences, while boys more frequently demonstrate antisocial behavior (20,21).Although many studies have identified both positive and negative correlates of internet use, there have been only a few studies using complex multivariate analyses to identify broader patterns of internet use and adolescent mental health (22,23). Less is known about how adolescents exhibiting different personalities and different emotional and behavioral patterns engage in internet use and what might be the consequences of this engagement. The aim of this study was to determine the specific patterns of internet use and mental health among adolescents. The following hypotheses were tested:H1: Problematic internet use is associated with externalized symptoms and other negative indicators of mental health. Exposure to victimizing and disturbing content on the internet is associated with internalized symptoms and negative indicators of mental health.H2: Prosocial internet use (aimed at connecting with peers and entertainment) and internet use for school purposes are associated with positive aspects of mental health.H3: Problematic internet use is present more often in young men, while exposure to disturbing content on the internet is more frequently experienced by young women.     

Image quality of mammography in Croatian nationwide screening program: comparison between various types of facilities

Purpose

The study was aimed to provide objective evidence about the mammographic image quality in Croatia, to compare it between different types of MG facilities and to identify the most common deficiencies and possible reasons as well as the steps needed to improve image quality.

Materials and methods

A total of 420 mammographic examinations collected from 84 mammographic units participating in the Croatian nationwide breast cancer screening program were reviewed in terms of four image quality categories: identification of patient and examination, breast positioning and compression, exposure and contrast, and artifacts. Those were rated using image evaluating system based on American College of Radiology and European Commission proposals. The results were compared among different types of mammographic units, and common image quality deficiencies were identified.

Results

Total image quality scores of 12.8, 16.1, 13.0 and 13.7 were found for general hospitals, university hospitals, private clinics and public healthcare centres, respectively. Average score for all mammographic units was 13.5 (out of 25 points). University hospitals were significantly better than all other mammography units in overall image quality, which was mostly contributed by better breast positioning practices. Private clinics showed the worst results in identification, exposure, contrast and artifacts.

Conclusions

Serious deficiencies in identification and breast positioning, which might compromise breast cancer screening outcome, were detected in our material. They occur mainly due to subjective reasons and could be corrected through additional staff training and improvement of working discipline.     

The increase in human plasma antioxidant capacity after red wine consumption is due to both plasma urate and wine polyphenols

By using red wine, dealcoholized red wine, polyphenols-stripped red wine, ethanol-water solution and water, the role of wine polyphenols and induction of plasma urate elevation on plasma antioxidant capacity was examined in humans (n=9 per beverage). Healthy males randomly consumed each beverage in a cross-over design. Plasma antioxidant capacity (measured by ferric reducing antioxidant power, FRAP), ethanol, catechin and urate concentrations were determined before and 30, 60, 90, 120 and 180 min after beverage intake. Dealcoholized red wine and polyphenols-stripped red wine induced similar increase in FRAP values which represented nearly half the effect of the original red wine. This indicates that consumption of red wine involves two separate mechanisms in elevation of plasma FRAP values and both wine phenols and plasma urate contribute to that effect.     

Glycaemic control and plasma lipoproteins in menopausal women with Type 2 diabetes treated with oral and transdermal combined hormone replacement therapy.

AIMS: To compare the effect of a fixed combination of an oestrogen (17-beta oestradiol) with a cyclical progestagen (norethisterone) on glycaemic control, plasma lipoproteins and haemostatic factors in women with Type 2 diabetes. METHODS: Oral and transdermal hormone replacement therapy (HRT) were compared to no HRT treatment in 33 postmenopausal women with Type 2 diabetes, in a 12-week randomised prospective open parallel group study. RESULTS: In the 11 women who received 12 weeks of oral HRT, there was a significant fall in total cholesterol (5.9+/-1.0 (S.D.) to 4.7+/-1.0 mmol l(-1), P=0.005), low density lipoprotein cholesterol (3.44+/-0.89 to 2.77+/-0.92 mmol l(-1), P=0.005) and triglyceride values (median (range)), (2.46 (0.96-5.52) to 2.29 (1.00-3.87) mmol l(-1), P<0.05). Oral HRT improved glycated haemoglobin (HbA(1c)) (7.4+/-1.4 to 6.8+/-1.2%, P< or =0.005). Oral HRT additionally reduced the cell adhesion factor E-selectin (82+/-33 to 60+/-20 microg l(-1), P<0.01) and factor VII (143+/-25 to 109+/-24% pooled plasma activity, P<0.01). No improvement in any of these parameters, except E-selectin (65+/-19 to 58+/-18 microg l(-1), P<0.01), occurred in the nine women receiving transdermal HRT, and no improvement occurred in the 13 controls randomised to no treatment. CONCLUSION: In women with Type 2 diabetes, cyclical oestrogen and progestagen taken orally for 12 weeks significantly improved glycaemic control and lipoprotein concentrations. These metabolic benefits were not apparent when a similar HRT preparation was administered transdermally.     

Insulin Clearance and the Incidence of Type 2 Diabetes in Hispanics and African Americans: The IRAS Family Study

OBJECTIVE

We aimed to identify factors that are independently associated with the metabolic clearance rate of insulin (MCRI) and to examine the association of MCRI with incident type 2 diabetes in nondiabetic Hispanics and African Americans.

RESEARCH DESIGN AND METHODS

We investigated 1,116 participants in the Insulin Resistance Atherosclerosis Study (IRAS) Family Study with baseline examinations from 2000 to 2002 and follow-up examinations from 2005 to 2006. Insulin sensitivity (S_I), acute insulin response (AIR), and MCRI were determined at baseline from frequently sampled intravenous glucose tolerance tests. MCRI was calculated as the ratio of the insulin dose over the incremental area under the curve of insulin. Incident diabetes was defined as fasting glucose ≥126 mg/dL or antidiabetic medication use by self-report.

RESULTS

We observed that S_I and HDL cholesterol were independent positive correlates of MCRI, whereas fasting insulin, fasting glucose, subcutaneous adipose tissue, visceral adipose tissue, and AIR were independent negative correlates (all P < 0.05) at baseline. After 5 years of follow-up, 71 (6.4%) participants developed type 2 diabetes. Lower MCRI was associated with a higher risk of incident diabetes after adjusting for demographics, lifestyle factors, HDL cholesterol, indexes of obesity and adiposity, and insulin secretion (odds ratio 2.01 [95% CI 1.30–3.10], P = 0.0064, per one-SD decrease in log_e-transformed MCRI).

CONCLUSIONS

Our data showed that lower MCRI predicts the incidence of type 2 diabetes.Insulin clearance is an integral component of insulin metabolism, as it regulates the cellular response to the hormone by decreasing insulin availability and mediates certain aspects of insulin action (1). The liver is the primary site of insulin clearance. Approximately 80% of endogenous insulin is removed by the liver, and the remainder is cleared by the kidneys and muscles (2). Clearance rates for insulin decrease in glucose intolerance (3), obesity (4), in particular abdominal obesity (5), hypertension (6), hepatic cirrhosis (7), and nonalcoholic fatty liver disease (8).Although the plasma concentration of insulin is largely determined by its rate of secretion and clearance, existing evidence suggests that increased insulin resistance is associated with reduced insulin clearance (9–12). Reduced insulin clearance has important physiological functions; for example, animal models have shown that decreased insulin clearance serves as a compensatory mechanism to preserve β-cell function and to maintain peripheral insulin levels in the states of insulin resistance (13,14). In addition, insulin clearance has been found to be a highly heritable trait in Mexican Americans, and specific haplotypes in the AMPD1 gene were associated with variation in insulin clearance (15).Despite its potential role in the etiology of diabetes, little is known about the factors that are independently associated with decreased insulin clearance. In addition, no previous study has investigated whether decreased insulin clearance predicts the risk of type 2 diabetes. In this study, we aimed to identify demographic and metabolic factors that are independently associated with the metabolic clearance rate of insulin (MCRI), and to examine its association with the 5-year risk of incident type 2 diabetes, using the data from a large, well-characterized cohort of Hispanics and African Americans with direct measurements of insulin metabolism (secretion, sensitivity, and clearance) and adipose tissue (visceral and subcutaneous) in the Insulin Resistance Atherosclerosis Study (IRAS) Family Study.     

A family based study implicates solute carrier family 1-member 3 (SLC1A3) gene in attention-deficit/hyperactivity disorder.

BACKGROUND: The glutamatergic system, the major excitatory neurotransmitter system in the central nervous system (CNS) has been proposed as contributing a possible role in the etiology of attention deficit hyperactivity disorder (ADHD). This is based upon observations from animal, neuroimaging, neuroanatomical and neuropsychological studies. Genes related to glutamate function are therefore good functional candidates for this disorder. The SLC1A3 (Solute Carrier Family 1, member 3) gene encodes a glial glutamate transporter which maps to chromosome 5p12, a region of linkage that coincides in two published ADHD genome scans so far. SLC1A3 is thus both a functional and positional candidate gene for ADHD. METHODS: We have undertaken detailed association analysis of SLC1A3 using a multi-stage approach for candidate gene analysis. RESULTS: In a family-based sample (n = 299) we found a significant association between marker rs2269272 (p = .007) and ADHD. Two, two-marker haplotypes, rs2269272/rs3776581 (p = .016) and rs2269272/rs2032893 (p = .013) also yielded evidence of association. CONCLUSIONS: The results of our study suggest that genetic variation in SLC1A3 may contribute to susceptibility to ADHD.