Assessment of laminate technique using glass ionomer and resin composite for restoration of root filled teeth

Objective

To evaluate the open laminate technique using glass ionomer cements (GIC) in association with a low shrink composite for restoring root filled premolars.

Methods

Extensive MOD cavities plus endodontic access and root filling were performed in intact extracted maxillary premolars. Three restoration types were evaluated: (1) resin composite alone; (2) resin-modified GIC (RM-GIC) open laminate plus resin composite; (3) conventional GIC open laminate plus resin composite (n = 8 for all groups and tests). Three tests were conducted to assess restorations: (A) inward cusp deflection during light curing, using DCDTs; (B) fracture strength using a ramped oblique load at 45° to the long axis in a servohydraulic testing machine in comparison with intact and unrestored teeth; (C) proximal marginal leakage using methylene blue dye and the effect of thermocycling. Data were analysed using 1-way ANOVA for cuspal deflection and fracture strength and Fisher's exact test for leakage.

Results

Laminate restorations resulted in significantly less cuspal deflection compared with resin composite (4.2 ± 1.2 μm for RM-GIC and 5.1 ± 2.3 μm for conventional GIC vs. 12.2 ± 2.6 μm for composite, P < 0.001). Fracture strength was not significantly different among all groups. Failure with all restorations was predominantly adhesive at the tooth-restoration interface. The two laminate groups showed significantly better marginal seal than composite alone, but sealing ability of conventional GIC deteriorated after thermocycling.

Conclusions

Laminate restoration of root filled teeth had beneficial effects in terms of reducing cuspal deflection and marginal seal, with acceptable fracture strength.     

Flare-ups in endodontics and their relationship to various medicaments

The purpose of this research is to investigate the frequency of endodontic flare-ups using a visual analogue scale. Definitions of flare-ups vary widely as does their reported frequency. A flare-up was defined as an increase of 20 or more points on the visual analogue scale for a given tooth, within the periods of 4 h and 24 h after the initial treatment appointment. The data from a previous study were used to determine the incidence of flare-ups after using three modalities (Ledermix, calcium hydroxide and no medication) to manage patients presenting for relief of pain of endodontic origin. A statistical analysis showed that there were no significant differences in flare-up rates at both the 4-h and 24-h periods between the three modalities. Further research is required using the above definition of a flare-up and standardising treatment protocols.     

Obesity is Associated with Worse Outcomes Among Abdominal Trauma Patients Undergoing Laparotomy: A Propensity-Matched Nationwide Cohort Study

Introduction

Obesity is associated with increased morbidity and mortality in abdominal trauma patients. The characteristics of abdominal trauma patients with poor outcomes related to obesity require evaluation. We hypothesize that obesity is related to increased mortality and length of stay (LOS) among abdominal trauma patients undergoing laparotomies.

Methods

Abdominal trauma patients were identified from the National Trauma Data Bank between 2013 and 2015. Patients who received laparotomies were analyzed using propensity score matching (PSM) to evaluate the mortality rate and LOS between obese and non-obese patients. Patients without laparotomies were analyzed as a control group using PSM cohort analysis.

Results

A total of 33,798 abdominal trauma patients were evaluated, 10,987 of them received laparotomies. Of these patients, the proportion of obesity in deceased patients was significantly higher when compared to the survivors (33.1% vs. 26.2%, p < 0.001). Elevation of one kg/m² of body mass index independently resulted in 2.5% increased odds of mortality. After a well-balanced PSM, obese patients undergoing laparotomies had significantly higher mortality rates [3.7% vs. 2.4%, standardized difference (SD) = 0.241], longer hospital LOS (11.1 vs. 9.6 days, SD = 0.135), and longer intensive care unit LOS (3.5 vs. 2.3 days, SD = 0.171) than non-obese patients undergoing laparotomies.

Conclusions

Obesity is associated with increased mortality in abdominal trauma patients who received laparotomies versus those who did not. Obesity requires a careful evaluation of alternatives to laparotomy in injured patients.

     

Oxidative metabolism of the human eosinophil

We have compared the oxidative metabolism of human eosinophils (80%-90% purity) to that of neutrophils. Hexose monophosphate (HMP) shunt activity of eosinophils was higher than that of neutrophils under either resting or phagocytizing conditions. Eosinophil HMP shunt activity also was stimulated by phorbol myristate acetate, a membrane- active agent. Eosinophils showed a marked incorporation of 125I into trichloroacetic acid-insoluble material under resting conditions, which increased markedly during phagocytosis. Eosinophils likewise showed a greater reduction of nitroblue tetrazolium dye during phagocytosis than did neutrophils. Measurement of other parameters of oxidative metabolism indicated that eosinophils generated superoxide anion following phagocytosis and also elicited a burst of chemiluminescence similar to that observed during phagocytosis by neutrophils. Measurement of NADPH oxidase activity demonstrated that this enzyme was 3-6 times more active in fractions isolated from eosinophils than in corresponding fractions isolated from neutrophils; this was observed over a range of substrate concentrations. The eosinophil enzyme sedimented differently than the neutrophil enzyme with differential centrifugation; neither showed sedimentation characteristics of peroxidase. These data indicate that eosinophils possess a similar, although in some ways more potent, oxidative burst than neutrophils and are consistent with a role for NADPH oxidase in the initiation of that burst.     

Direct medical costs and their predictors in patients with rheumatoid arthritis: a three-year study of 7,527 patients

OBJECTIVE: To estimate total direct medical costs in persons with rheumatoid arthritis (RA) and to characterize predictors of these costs. METHODS: Patients (n = 7,527) participating in a longitudinal study of outcome in RA completed 25,050 semiannual questionnaires from January 1999 through December 2001. From these we determined direct medical care costs converted to 2001 US dollars using the consumer price index. We used generalized estimating equations to examine potential predictors of the costs. Monte Carlo simulations and sensitivity analyses were performed to evaluate the varying prevalence and cost of biologic therapy. RESULTS: The mean total annual direct medical care cost in 2001 for a patient with RA was 9,519 US dollars. Drug costs were 6,324 US dollars (66% of the total), while hospitalization costs were only 1,573 US dollars (17%). Approximately 25% of patients received biologic therapy. The mean total annual direct cost for patients receiving biologic agents was 19,016 US dollars per year, while the cost for those not receiving biologic therapy was 6,164 US dollars. RA patients who were in the worst quartile of functional status, as measured by the Health Assessment Questionnaire, experienced direct medical costs for the subsequent year that were 5,022 US dollars more than the costs incurred by those in the best quartile. Physical status as determined by the Short Form 36 physical component scale had a similar large effect on RA costs, as did comorbidity. Medical insurance type played a more limited role. However, those without insurance had substantially lower service utilization and costs, and health maintenance organization patients had lower drug costs and total medical costs. Increased years of education, increased income, and majority ethnic status were all associated with increased drug costs but not hospitalization costs. Costs in all categories decreased after age 65 years. CONCLUSION: Estimates of direct medical costs for patients with RA are substantially higher than cost estimates before the biologic therapy era, and costs are now driven predominantly by the cost of drugs, primarily biologic agents. RA patients with poor function continue to incur substantially higher costs, as do those with comorbid conditions, and sociodemographic characteristics also play an important role in determination of costs.     

Exposure to Fine Particulate Matter during Pregnancy and Risk of Preterm Birth among Women in New Jersey,Ohio, and Pennsylvania, 2000–2005

Background: Particulate matter ≤ 2.5 μm in aerodynamic diameter (PM_2.5) has been variably associated with preterm birth (PTB).Objective: We classified PTB into four categories (20–27, 28–31, 32–34, and 35–36 weeks completed gestation) and estimated risk differences (RDs) for each category in association with a 1-μg/m³ increase in PM_2.5 exposure during each week of gestation.Methods: We assembled a cohort of singleton pregnancies that completed ≥ 20 weeks of gestation during 2000–2005 using live birth certificate data from three states (Pennsylvania, Ohio, and New Jersey) (n = 1,940,213; 8% PTB). We estimated mean PM_2.5 exposures for each week of gestation from monitor-corrected Community Multi-Scale Air Quality modeling data. RDs were estimated using modified Poisson linear regression and adjusted for maternal race/ethnicity, marital status, education, age, and ozone.Results: RD estimates varied by exposure window and outcome period. Average PM_2.5 exposure during the fourth week of gestation was positively associated with all PTB outcomes, although magnitude varied by PTB category [e.g., for a 1-μg/m³ increase, RD = 11.8 (95% CI: –6, 29.2); RD = 46 (95% CI: 23.2, 68.9); RD = 61.1 (95% CI: 22.6, 99.7); and RD = 28.5 (95% CI: –39, 95.7) for preterm births during 20–27, 28–31, 32–34, and 35–36 weeks, respectively]. Exposures during the week of birth and the 2 weeks before birth also were positively associated with all PTB categories.Conclusions: Exposures beginning around the time of implantation and near birth appeared to be more strongly associated with PTB than exposures during other time periods. Because particulate matter exposure is ubiquitous, evidence of effects of PM_2.5 exposure on PTB, even if small in magnitude, is cause for concern.Citation: Rappazzo KM, Daniels JL, Messer LC, Poole C, Lobdell DT. 2014. Exposure to fine particulate matter during pregnancy and risk of preterm birth among women in New Jersey, Ohio, and Pennsylvania, 2000–2005. Environ Health Perspect 122:992–997; http://dx.doi.org/10.1289/ehp.1307456     

National Trends in Smoking Behaviors Among Mexican,Puerto Rican,and Cuban Men and Women in the United States

Objectives. We examined trends in smoking behaviors across 2 periods among Mexicans, Puerto Ricans, and Cubans in the United States.Methods. We analyzed data from the 1992–2007 Tobacco Use Supplements to the Current Population Survey. We constructed 2 data sets (1990s vs 2000s) to compare smoking behaviors between the 2 periods.Results. Significant decreases in ever, current, and heavy smoking were accompanied by increases in light and intermittent smoking across periods for all Latino groups, although current smoking rates among Puerto Rican women did not decline. Adjusted logistic regression models revealed that in the 2000s, younger Mexicans and those interviewed in English were more likely to be light and intermittent smokers. Mexican and Cuban light and intermittent smokers were less likely to be advised by healthcare professionals to quit smoking. Mexicans and Puerto Ricans who were unemployed and Mexicans who worked outdoors were more likely to be heavy smokers.Conclusions. Increases in light and intermittent smoking among Mexican, Puerto Rican, and Cuban Americans suggest that targeted efforts to further reduce smoking among Latinos may benefit by focusing on such smokers.Since 2000, Latinos have experienced the largest population growth of all US racial/ethnic groups, making Latinos the largest ethnic minority group in the country at 16.3% of the population.1 Mexicans, Puerto Ricans, and Cubans are the 3 largest Latino national and family background groups in the United States.1 The leading causes of death among Latinos are coronary heart disease and cancer, both of which are strongly associated with tobacco use.2,3 Although differences in smoking rates by Latino national origin groups have been found,4–6 very little research has examined trends in smoking behaviors for various Latino national origin groups by gender in the United States.The aggregation of smoking rates for various Latino national origin groups masks important variations within the population group.4 For example, smoking prevalence rates as determined by national data from 2008 are highest among Cubans (21.5%), followed by Mexicans (20.1%), and Puerto Ricans (18.6%).3 Puerto Ricans and Cubans are also more likely to be current smokers than are Mexicans.7 Furthermore, although research grounded on a nationally representative sample found that Latinos were approximately 4.5 times more likely to be light smokers than were non-Hispanic Whites,8 that study provided only aggregated rates for all Latinos and did not differentiate between national origin groups. Gender differences have also been reported among disaggregated Latino groups. A higher prevalence of smoking has been reported among Mexican (25.0%), Puerto Rican (27.6%), and Cuban (24.7%) men than among Mexican (10.4%), Puerto Rican (24.2%), and Cuban (12.4%) women.7 The lower rates of smoking among women have been consistent in surveys of Latinos.5,7,9 Results from these studies, although informative, have generally been determined by aggregated Latino data or data from a single survey time point. Although such data are valuable and can demonstrate existing gender differences, national-level trends from Latino nationality groups in the United States add valuable information that have not been previously reported.Previous research has also identified social and environmental factors associated with Latinos’ smoking behaviors. Acculturation to mainstream US culture plays a significant role in one’s health behaviors,10 and as Latinos acculturate, their smoking behaviors become similar to those of non-Hispanic Whites.7 Existing research has also revealed that Latinos are less likely to quit smoking,11 receive tobacco screening, and be advised to quit by a physician than are non-Hispanic Whites.12–15 A health professionals’ advice to quit smoking has been found to increase the likelihood that a smoker will successfully quit.16,17 Lastly, workplace smoking policies have also influenced smoking prevalence and intensity.18–20 Work environments adopting a smoke-free policy saw a 14% decrease in individuals’ smoking.21 When examining national-level smoking behaviors among Latinos, it is important to account for social and environmental factors such as acculturation, physician advice to quit smoking, and work environment smoking policies, as they may influence smoking behaviors.Existing research on smoking behaviors among Latino national origin groups has been predicated on data from specific regions of the United States.4,22–25 Although regional data are important for the development of community-level interventions,4 national-level data provide an overview of the country’s progress in tobacco control as well as remaining and emerging challenges for Latinos nationwide. We compared smoking behaviors across 2 periods, about a decade apart, among Mexicans, Puerto Ricans, and Cubans. Our goals in these analyses were (1) to compare Latino national origin groups across 2 periods to examine factors affecting changes in smoking behavior within and between groups, and (2) to evaluate demographic factors that influence current smoking behaviors within Latino national origin groups in the most recent period available. Examining long-term national trends in Latino smoking behaviors may prove vital to policymakers, public health officials, community workers, and interventionists as they address tobacco-related issues.     

Genome-wide signals of positive selection in human evolution

The role of positive selection in human evolution remains controversial. On the one hand, scans for positive selection have identified hundreds of candidate loci, and the genome-wide patterns of polymorphism show signatures consistent with frequent positive selection. On the other hand, recent studies have argued that many of the candidate loci are false positives and that most genome-wide signatures of adaptation are in fact due to reduction of neutral diversity by linked deleterious mutations, known as background selection. Here we analyze human polymorphism data from the 1000 Genomes Project and detect signatures of positive selection once we correct for the effects of background selection. We show that levels of neutral polymorphism are lower near amino acid substitutions, with the strongest reduction observed specifically near functionally consequential amino acid substitutions. Furthermore, amino acid substitutions are associated with signatures of recent adaptation that should not be generated by background selection, such as unusually long and frequent haplotypes and specific distortions in the site frequency spectrum. We use forward simulations to argue that the observed signatures require a high rate of strongly adaptive substitutions near amino acid changes. We further demonstrate that the observed signatures of positive selection correlate better with the presence of regulatory sequences, as predicted by the ENCODE Project Consortium, than with the positions of amino acid substitutions. Our results suggest that adaptation was frequent in human evolution and provide support for the hypothesis of King and Wilson that adaptive divergence is primarily driven by regulatory changes.The rate and patterns of positive selection are of fundamental interest for the study of human evolution. Population genomic studies should, in principle, allow us to quantify positive selection from its expected signatures in sequence polymorphism and divergence data. Surprisingly, despite the sequencing of thousands of human genomes (The 1000 Genomes Project Consortium 2012) and the availability of whole-genome sequences of closely related species, the extent to which adaptation has left identifiable signatures in the patterns of polymorphism in the human genome remains highly controversial (Akey 2009; Hernandez et al. 2011).On the one hand, recent studies have identified a large number of loci showing signatures of recent selective sweeps (Voight et al. 2006; Sabeti et al. 2007; Williamson et al. 2007; Pickrell et al. 2009; Grossman et al. 2013), and McDonald-Kreitman (MK) analyses inferred that ∼10%–20% of amino acid changes have been adaptive in human evolution (Boyko et al. 2008; Messer and Petrov 2013). Consistently, regions of high functional density, high rate of amino acid substitutions, and low recombination all show reduced levels of neutral diversity (Cai et al. 2009; Lohmueller et al. 2011), as expected under recurrent selective sweeps in functional regions.On the other hand, there are reasons to question the notion that adaptation left clear signatures in the human genome. First, different scans for positive selection have identified largely nonoverlapping sets of candidates (Akey 2009), which could be due to a high rate of false positives. Second, MK analyses can be confounded by a number of factors, such as perturbations left by demographic events and by the presence of slightly deleterious mutations (Eyre-Walker and Keightley 2009; Messer and Petrov 2013), and some MK analyses have failed to find evidence for adaptation in the human lineage (Eyre-Walker and Keightley 2009). Finally, it has been shown that background selection (BGS) (Charlesworth et al. 1993), a process in which deleterious mutations remove linked neutral variation from the population, reduces levels of polymorphism in regions of higher functional density and low recombination, providing an alternative explanation for the observation of these correlations in the human genome.One signature of positive selection—lower levels of neutral variation near functional substitutions (Andolfatto 2007; Macpherson et al. 2007; Cai et al. 2009)—is not generally expected under BGS and should therefore provide the clearest genomic evidence for the action of positive selection. While this signature was found in the human genome by Cai et al. (2009), it could not be detected by two recent studies using the newest large-scale data sets of human diversity (Hernandez et al. 2011; Lohmueller et al. 2011). In particular, Hernandez et al. (2011) searched for lower levels of neutral diversity near functional substitutions by contrasting levels of neutral diversity near nonsynonymous compared with synonymous substitutions. They did not find this signature in the human genome and, moreover, found that diversity might in fact be marginally higher near nonsynonymous substitutions. Simulations showed that this puts sharp limits on the amount of adaptation by classic selective sweeps in recent human evolution (Hernandez et al. 2011).However, it is likely that the study design of Hernandez et al. (2011) (also implemented in Drosophila by Sattath et al. 2011) is strongly biased against finding signatures of positive selection in the human genome and all other genomes with sharply variable levels of genomic constraint. This is because, as we show in the Results, nonsynonymous substitutions in the human genome tend to be located in regions of weaker constraint and thus weaker BGS compared with synonymous substitutions. These differences in levels of BGS should elevate neutral diversity near nonsynonymous compared with synonymous substitutions. The approach of Hernandez et al. (2011) would thus detect positive selection only if the reduction of diversity due to positive selection near nonsynonymous substitutions happens to be greater than the initial difference in the opposite direction due to BGS.Here we utilize a number of more sensitive approaches in the search for signatures of positive selection while attempting to reduce the confounding effects of BGS to the greatest extent possible. Our results suggest that positive selection was frequent in human history and might have involved adaptive mutations of substantial selective effect. We estimate that a few hundred strong adaptive events are likely to be detectable in the human genome, consistent with the latest scan for positive selection (Grossman et al. 2013). Moreover, we provide evidence that the majority of adaptive substitutions were due to cis-regulatory rather than protein-coding changes, consistent with the King and Wilson (1975) hypothesis that adaptive divergence is primarily driven by regulatory changes.