1,822 research outputs found
Early treatment of posterior crossbite - a randomised clinical trial
Background: The aim of this randomised clinical trial was to assess the effect of early orthodontic treatment in contrast to normal growth effects for functional unilateral posterior crossbite in the late deciduous and early mixed dentition by means of three-dimensional digital model analysis.
Methods: This randomised clinical trial was assessed to analyse the orthodontic treatment effects for patients with functional unilateral posterior crossbite in the late deciduous and early mixed dentition using a two-step procedure: initial maxillary expansion followed by a U-bow activator therapy. In the treatment group 31 patients and in the control group 35 patients with a mean age of 7.3 years (SD 2.1) were monitored. The time between the initial assessment (T1) and the follow-up (T2) was one year. The orthodontic analysis was done by a three-dimensional digital model analysis. Using the ‘Digimodel’ software, the orthodontic measurements in the maxilla and mandible and for the midline deviation, the overjet and overbite were recorded.
Results: Significant differences between the control and the therapy group at T2 were detected for the anterior, median and posterior transversal dimensions of the maxilla, the palatal depth, the palatal base arch length, the maxillary arch length and inclination, the midline deviation, the overjet and the overbite.
Conclusions: Orthodontic treatment of a functional unilateral posterior crossbite with a bonded maxillary expansion device followed by U-bow activator therapy in the late deciduous and early mixed dentition is an effective therapeutic method, as evidenced by the results of this RCT. It leads to three-dimensional therapeutically induced maxillary growth effects. Dental occlusion is significantly improved, and the prognosis for normal craniofacial growth is enhanced
Genetically determined height and coronary artery disease.
BACKGROUND: The nature and underlying mechanisms of an inverse association between adult height and the risk of coronary artery disease (CAD) are unclear. METHODS: We used a genetic approach to investigate the association between height and CAD, using 180 height-associated genetic variants. We tested the association between a change in genetically determined height of 1 SD (6.5 cm) with the risk of CAD in 65,066 cases and 128,383 controls. Using individual-level genotype data from 18,249 persons, we also examined the risk of CAD associated with the presence of various numbers of height-associated alleles. To identify putative mechanisms, we analyzed whether genetically determined height was associated with known cardiovascular risk factors and performed a pathway analysis of the height-associated genes. RESULTS: We observed a relative increase of 13.5% (95% confidence interval [CI], 5.4 to 22.1; P<0.001) in the risk of CAD per 1-SD decrease in genetically determined height. There was a graded relationship between the presence of an increased number of height-raising variants and a reduced risk of CAD (odds ratio for height quartile 4 versus quartile 1, 0.74; 95% CI, 0.68 to 0.84; P<0.001). Of the 12 risk factors that we studied, we observed significant associations only with levels of low-density lipoprotein cholesterol and triglycerides (accounting for approximately 30% of the association). We identified several overlapping pathways involving genes associated with both development and atherosclerosis. CONCLUSIONS: There is a primary association between a genetically determined shorter height and an increased risk of CAD, a link that is partly explained by the association between shorter height and an adverse lipid profile. Shared biologic processes that determine achieved height and the development of atherosclerosis may explain some of the association. (Funded by the British Heart Foundation and others.)
Nonparametric Regression with Trapezoidal Fuzzy Data
This paper is an investigation into nonparametric fuzzy regression with crisp input and asymmetric trapezoidal fuzzy output. It analyzes the a nonparametric techniques in statistics, namely local linear smoothing (L-L-S) with trapezoidal fuzzy data to obtain the best smoothing parameters. In addition, it makes an analysis on one real-world datasets and calculates the goodness of fit to illustrate the application of the proposed method.
DOI: 10.17762/ijritcc2321-8169.15067
A comprehensive 1000 Genomes-based genome-wide association meta-analysis of coronary artery disease
Existing knowledge of genetic variants affecting risk of coronary artery disease (CAD) is largely based on genome-wide association studies (GWAS) analysis of common SNPs. Leveraging phased haplotypes from the 1000 Genomes Project, we report a GWAS meta-analysis of 185 thousand CAD cases and controls, interrogating 6.7 million common (MAF>0.05) as well as 2.7 million low frequency (0.005<MAF<0.05) variants. In addition to confirmation of most known CAD loci, we identified 10 novel loci, eight additive and two recessive, that contain candidate genes that newly implicate biological processes in vessel walls. We observed intra-locus allelic heterogeneity but little evidence of low frequency variants with larger effects and no evidence of synthetic association. Our analysis provides a comprehensive survey of the fine genetic architecture of CAD showing that genetic susceptibility to this common disease is largely determined by common SNPs of small effect siz
Natriuretic peptides and integrated risk assessment for cardiovascular disease. an individual-participant-data meta-analysis
BACKGROUND: Guidelines for primary prevention of cardiovascular diseases focus on prediction of coronary heart disease and stroke. We assessed whether or not measurement of N-terminal-pro-B-type natriuretic peptide (NT-proBNP) concentration could enable a more integrated approach than at present by predicting heart failure and enhancing coronary heart disease and stroke risk assessment.
METHODS: In this individual-participant-data meta-analysis, we generated and harmonised individual-participant data from relevant prospective studies via both de-novo NT-proBNP concentration measurement of stored samples and collection of data from studies identified through a systematic search of the literature (PubMed, Scientific Citation Index Expanded, and Embase) for articles published up to Sept 4, 2014, using search terms related to natriuretic peptide family members and the primary outcomes, with no language restrictions. We calculated risk ratios and measures of risk discrimination and reclassification across predicted 10 year risk categories (ie, <5%, 5% to <7·5%, and ≥7·5%), adding assessment of NT-proBNP concentration to that of conventional risk factors (ie, age, sex, smoking status, systolic blood pressure, history of diabetes, and total and HDL cholesterol concentrations). Primary outcomes were the combination of coronary heart disease and stroke, and the combination of coronary heart disease, stroke, and heart failure.
FINDINGS: We recorded 5500 coronary heart disease, 4002 stroke, and 2212 heart failure outcomes among 95 617 participants without a history of cardiovascular disease in 40 prospective studies. Risk ratios (for a comparison of the top third vs bottom third of NT-proBNP concentrations, adjusted for conventional risk factors) were 1·76 (95% CI 1·56-1·98) for the combination of coronary heart disease and stroke and 2·00 (1·77-2·26) for the combination of coronary heart disease, stroke, and heart failure. Addition of information about NT-proBNP concentration to a model containing conventional risk factors was associated with a C-index increase of 0·012 (0·010-0·014) and a net reclassification improvement of 0·027 (0·019-0·036) for the combination of coronary heart disease and stroke and a C-index increase of 0·019 (0·016-0·022) and a net reclassification improvement of 0·028 (0·019-0·038) for the combination of coronary heart disease, stroke, and heart failure.
INTERPRETATION: In people without baseline cardiovascular disease, NT-proBNP concentration assessment strongly predicted first-onset heart failure and augmented coronary heart disease and stroke prediction, suggesting that NT-proBNP concentration assessment could be used to integrate heart failure into cardiovascular disease primary prevention
A microRNA negative feedback loop downregulates vesicle transport and inhibits fear memory
The SNARE-mediated vesicular transport pathway plays major roles in synaptic remodeling associated with formation of long-term memories, but the mechanisms that regulate this pathway during memory acquisition are not fully understood. Here we identify miRNAs that are up-regulated in the rodent hippocampus upon contextual fear-conditioning and identify the vesicular transport and synaptogenesis pathways as the major targets of the fear-induced miRNAs. We demonstrate that miR-153, a member of this group, inhibits the expression of key components of the vesicular transport machinery, and down-regulates Glutamate receptor A1 trafficking and neurotransmitter release. MiR-153 expression is specifically induced during LTP induction in hippocampal slices and its knockdown in the hippocampus of adult mice results in enhanced fear memory. Our results suggest that miR-153, and possibly other fear-induced miRNAs, act as components of a negative feedback loop that blocks neuronal hyperactivity at least partly through the inhibition of the vesicular transport pathway.Brain & Behavior Research Foundation (Young Investigator Award)JPB Foundatio
Fifteen new risk loci for coronary artery disease highlight arterial-wall-specific mechanisms
Coronary artery disease (CAD) is a leading cause of morbidity and mortality worldwide. Although 58 genomic regions have been associated with CAD thus far, most of the heritability is unexplained, indicating that additional susceptibility loci await identification. An efficient discovery strategy may be larger-scale evaluation of promising associations suggested by genome-wide association studies (GWAS). Hence, we genotyped 56,309 participants using a targeted gene array derived from earlier GWAS results and performed meta-analysis of results with 194,427 participants previously genotyped, totaling 88,192 CAD cases and 162,544 controls. We identified 25 new SNP-CAD associations (P < 5 × 10(-8), in fixed-effects meta-analysis) from 15 genomic regions, including SNPs in or near genes involved in cellular adhesion, leukocyte migration and atherosclerosis (PECAM1, rs1867624), coagulation and inflammation (PROCR, rs867186 (p.Ser219Gly)) and vascular smooth muscle cell differentiation (LMOD1, rs2820315). Correlation of these regions with cell-type-specific gene expression and plasma protein levels sheds light on potential disease mechanisms
Quantitative plane-resolved crystal growth and dissolution kinetics by coupling in situ optical microscopy and diffusion models : the case of salicylic acid in aqueous solution
The growth and dissolution kinetics of salicylic acid crystals are investigated in situ by focusing on individual microscale crystals. From a combination of optical microscopy and finite element method (FEM) modeling, it was possible to obtain a detailed quantitative picture of dissolution and growth dynamics for individual crystal faces. The approach uses real-time in situ growth and dissolution data (crystal size and shape as a function of time) to parametrize a FEM model incorporating surface kinetics and bulk to surface diffusion, from which concentration distributions and fluxes are obtained directly. It was found that the (001) face showed strong mass transport (diffusion) controlled behavior with an average surface concentration close to the solubility value during growth and dissolution over a wide range of bulk saturation levels. The (1̅10) and (110) faces exhibited mixed mass transport/surface controlled behavior, but with a strong diffusive component. As crystals became relatively large, they tended to exhibit peculiar hollow structures in the end (001) face, observed by interferometry and optical microscopy. Such features have been reported in a number of crystals, but there has not been a satisfactory explanation for their origin. The mass transport simulations indicate that there is a large difference in flux across the crystal surface, with high values at the edge of the (001) face compared to the center, and this flux has to be redistributed across the (001) surface. As the crystal grows, the redistribution process evidently can not be maintained so that the edges grow at the expense of the center, ultimately creating high index internal structures. At later times, we postulate that these high energy faces, starved of material from solution, dissolve and the extra flux of salicylic acid causes the voids to close
Digital subtraction radiographic analysis of the combination of bioabsorbable membrane and bovine morphogenetic protein pool in human periodontal infrabony defects
Objectives: This study assessed the bone density gain and its relationship with the
periodontal clinical parameters in a case series of a regenerative therapy procedure.
Material and Methods: Using a split-mouth study design, 10 pairs of infrabony defects from
15 patients were treated with a pool of bovine bone morphogenetic proteins associated with
collagen membrane (test sites) or collagen membrane only (control sites). The periodontal
healing was clinically and radiographically monitored for six months. Standardized presurgical
and 6-month postoperative radiographs were digitized for digital subtraction
analysis, which showed relative bone density gain in both groups of 0.034 ± 0.423 and
0.105 ± 0.423 in the test and control group, respectively (p>0.05). Results: As regards the
area size of bone density change, the influence of the therapy was detected in 2.5 mm2 in
the test group and 2 mm2 in the control group (p>0.05). Additionally, no correlation was
observed between the favorable clinical results and the bone density gain measured by
digital subtraction radiography (p>0.05). Conclusions: The findings of this study suggest
that the clinical benefit of the regenerative therapy observed did not come with significant
bone density gains. Long-term evaluation may lead to a different conclusions
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