Effect of alternative photostimulable phosphor plates erasing times on subjective digital image quality

Objective

To evaluate the influence of alternative erasing times of DenOptix® (Dentsply/Gendex, Chicargo, IL) digital plates on subjective image quality and the probability of double exposure image not occurring.

Methods

Human teeth were X-rayed with phosphor plates using ten different erasing times. Two observers evaluated the images for subjective image quality (sharpness, brightness, contrast, enamel definition, dentin definition and dentin-enamel junction definition) and for the presence or absence of double exposure image. Spearman''s correlation analysis and ANOVA was performed to verify the existence of a linear association between the subjective image quality parameters and the alternative erasing times. A contingency table was constructed to evaluate the agreement among the observers, and a binominal logistic regression was performed to verify the correlation between the erasing time and the probability of double exposure image not occurring.

Results

All 6 parameters of image quality were rated high by the examiners for the erasing times between 25 s and 130 s. The same erasing time range, from 25 to 130 s, was considered a safe erasing time interval, with no probability of a double exposure image occurring.

Conclusions

The alternative erasing times from 25 s to 130 s showed high image quality and no probability of double image occurrence. Thus, it is possible to reduce the operating time of the DenOptix® digital system without jeopardizing the diagnostic task.     

"Watching a person who knows how to cook, you'll learn a lot". Linked lives, cultural transmission, and the food choices of Puerto Rican girls

In-depth individual interviews were conducted with mainland- and island-dwelling Puerto Rican girls (n=23) to determine how migration, acculturation, and family contexts influenced food choices. Interview data from girls with diverse migration experiences (U.S. mainland raised, recent migrants to U.S. mainland, and Puerto Rico raised) were triangulated with extensive participant observation conducted in New York State and Puerto Rico. Data analysis using a ground theory approach revealed that participants' access to traditional foods varied in three domains: mothers' (cultural orientation, health, work, and cooking skills); household (composition, presence of Puerto Rican grandmother, and cooking skills); and girls' (migration experience, food preferences and values, and cooking skills) characteristics. Four food choice types emerged from participant narratives that differed in these domains: everybody cooks, tradition keeper, seeker, and on my own. Varied language orientations and migration experiences were represented among girls across all four food choice types, ranging from consistent to limited access to traditional food, demonstrating the limitations of one-dimensional models for understanding dietary acculturation. Findings demonstrate how a multidimensional, culture-specific model, including both cultural and structural characteristics, can influence dietary acculturation at the family and household level and food choices among immigrant adolescent girls, and guide future research and interventions.     

An initial map of insertion and deletion (INDEL) variation in the human genome

Although many studies have been conducted to identify single nucleotide polymorphisms (SNPs) in humans, few studies have been conducted to identify alternative forms of natural genetic variation, such as insertion and deletion (INDEL) polymorphisms. In this report, we describe an initial map of human INDEL variation that contains 415,436 unique INDEL polymorphisms. These INDELs were identified with a computational approach using DNA re-sequencing traces that originally were generated for SNP discovery projects. They range from 1 bp to 9989 bp in length and are split almost equally between insertions and deletions, relative to the chimpanzee genome sequence. Five major classes of INDELs were identified, including (1) insertions and deletions of single-base pairs, (2) monomeric base pair expansions, (3) multi-base pair expansions of 2-15 bp repeat units, (4) transposon insertions, and (5) INDELs containing random DNA sequences. Our INDELs are distributed throughout the human genome with an average density of one INDEL per 7.2 kb of DNA. Variation hotspots were identified with up to 48-fold regional increases in INDEL and/or SNP variation compared with the chromosomal averages for the same chromosomes. Over 148,000 INDELs (35.7%) were identified within known genes, and 5542 of these INDELs were located in the promoters and exons of genes, where gene function would be expected to be influenced the greatest. All INDELs in this study have been deposited into dbSNP and have been integrated into maps of human genetic variation that are available to the research community.     

Do sleep problems or urinary incontinence predict falls in elderly women?

The objectives of this cross-sectional study were: (1) To determine if night-time sleep disturbance, daytime sleepiness, or urinary incontinence were associated with an increased risk of falling in older Australian women and (2) to explore the interrelationships between daytime sleepiness, night-time sleep problems, and urge incontinence. Participants were 782 ambulatory, community-dwelling women aged 75 to 86 recruited from within the existing Calcium Intake Fracture Outcome Study, in which women above 70 years were selected at random from the electoral roll. Daytime sleepiness, night-time sleep problems, urinary incontinence and falls data were collected via self-complete questionnaires. Thirty-five per cent of participants had fallen at least once in the past 12 months and 37.7% reported at least one night-time sleep problem. However, only 8.1% of the study sample experienced abnormal daytime sleepiness (Epworth Sleepiness Scale score > 10). Pure stress, pure urge, and mixed incontinence occurred in 36.8%, 3.7%, and 32.6% of participants respectively. In forward stepwise multiple logistic regression analysis, urge incontinence (OR 1.76; 95% CI 1.29 to 2.41) and abnormal daytime sleepiness (OR 2.05; 95% CI 1.21 to 3.49) were significant independent risk factors for falling after controlling for other falls risk factors (age, central nervous system drugs, cardiovascular drugs). As urge incontinence and abnormal daytime sleepiness were independently associated with an increased falls risk, effective management of these problems may reduce the risk of falling in older women.     

Differential expression of components of the cardiomyocyte adrenomedullin/intermedin receptor system following blood pressure reduction in nitric oxide-deficient hypertension

Adrenomedullin (AM) and intermedin (IMD; adrenomedulln-2) are vasodilator peptides related to calcitonin gene-related peptide (CGRP). The actions of these peptides are mediated by the calcitonin receptor-like receptor (CLR) in association with one of three receptor activity-modifying proteins. CGRP is selective for CLR/receptor activity modifying protein (RAMP)1, AM for CLR/RAMP2 and -3, and IMD acts at both CGRP and AM receptors. In a model of pressure overload induced by inhibition of nitric-oxide synthase, up-regulation of AM was observed previously in cardiomyocytes demonstrating a hypertrophic phenotype. The current objective was to examine the effects of blood pressure reduction on cardiomyocyte expression of AM and IMD and their receptor components. Nomega-nitro-L-arginine methyl ester (L-NAME) (35 mg/kg/day) was administered to rats for 8 weeks, with or without concurrent administration of hydralazine (50 mg/kg/day) and hydrochlorothiazide (7.5 mg/kg/day). In left ventricular cardiomyocytes from L-NAME-treated rats, increases (-fold) in mRNA expression were 1.6 (preproAM), 8.4 (preproIMD), 3.4 (CLR), 4.1 (RAMP1), 2.8 (RAMP2), and 4.4 (RAMP3). Hydralazine/hydrochlorothiazide normalized systolic blood pressure (BP) and abolished mRNA up-regulation of hypertrophic markers sk-alpha-actin and BNP and of preproAM, CLR, RAMP2, and RAMP3 but did not normalize cardiomyocyte width nor preproIMD or RAMP1 mRNA expression. The robust increase in IMD expression indicates an important role for this peptide in the cardiac pathology of this model but, unlike AM, IMD is not associated with pressure overload upon the myocardium. The concordance of IMD and RAMP1 up-regulation indicates a CGRP-type receptor action; considering also a lack of response to BP reduction, IMD may, like CGRP, have an anti-ischemic function.     

Enhancement of erythrosine-mediated photodynamic therapy of Streptococcus mutans biofilms by light fractionation

OBJECTIVES: We aimed to increase the bacterial cell killing efficacy of erythrosine-mediated photodynamic therapy (PDT) of Streptococcus mutans biofilms by fractionating the delivered light dose into a series of shorter pulses. METHODS: S. mutans biofilms of 200 microm thickness were grown in a constant-depth film fermenter (CDFF). Biofilms were incubated with 22 microM erythrosine before being irradiated with white light for increasing periods of time. We also used light dose fractionation to deliver the same overall dose of light in a series of shorter pulses separated by dark periods. Bacterial cell killing as a result of each killing protocol was quantified by colony counting. RESULTS: A 2 log10 of bacterial cell killing was achieved with 5 min of continuous white light irradiation. For time periods longer than 5 min the amount of killing increased more slowly, which was probably due to photobleaching of the erythrosine. Fractionation of the light dose into 5 x 1 min doses separated by dark recovery periods of 5 min increased the amount of bacterial killing by 1 log10 compared with 5 min continuous irradiation. Further fractionation of the light dose into 10x 30 s doses separated by 2 min recovery periods resulted in 3.7 log10 of cell kill, an improvement of 1.7 log10 compared with the continuous irradiation protocol. CONCLUSIONS: Erythrosine-mediated PDT of S. mutans biofilms can be further enhanced by fractionation of the applied light dose.