29 research outputs found
A Body Shape Index (ABSI) achieves better mortality risk stratification than alternative indices of abdominal obesity: results from a large European cohort
Abstract: Abdominal and general adiposity are independently associated with mortality, but there is no consensus on how best to assess abdominal adiposity. We compared the ability of alternative waist indices to complement body mass index (BMI) when assessing all-cause mortality. We used data from 352,985 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) and Cox proportional hazards models adjusted for other risk factors. During a mean follow-up of 16.1 years, 38,178 participants died. Combining in one model BMI and a strongly correlated waist index altered the association patterns with mortality, to a predominantly negative association for BMI and a stronger positive association for the waist index, while combining BMI with the uncorrelated A Body Shape Index (ABSI) preserved the association patterns. Sex-specific cohort-wide quartiles of waist indices correlated with BMI could not separate high-risk from low-risk individuals within underweight (BMI < 18.5 kg/m2) or obese (BMI ≥ 30 kg/m2) categories, while the highest quartile of ABSI separated 18–39% of the individuals within each BMI category, which had 22–55% higher risk of death. In conclusion, only a waist index independent of BMI by design, such as ABSI, complements BMI and enables efficient risk stratification, which could facilitate personalisation of screening, treatment and monitoring
Differential Expression of OCT4 Pseudogenes in Pluripotent and Tumor Cell Lines
Objective: The human OCT4 gene, the most important pluripotency marker, can generate
at least three different transcripts (OCT4A, OCT4B, and OCT4B1) by alternative splicing.
OCT4A is the main isoform responsible for the stemness property of embryonic stem (ES)
cells. There also exist eight processed OCT4 pseudogenes in the human genome with
high homology to the OCT4A, some of which are transcribed in various cancers. Recent
conflicting reports on OCT4 expression in tumor cells and tissues emphasize the need to
discriminate the expression of OCT4A from other variants as well as OCT4 pseudogenes.
Materials and Methods: In this experimental study, DNA sequencing confirmed the authenticity
of transcripts of OCT4 pseudogenes and their expression patterns were investigated
in a panel of different human cell lines by reverse transcription-polymerase chain
reaction (RT-PCR).
Results: Differential expression of OCT4 pseudogenes in various human cancer and
pluripotent cell lines was observed. Moreover, the expression pattern of OCT4-pseudogene
3 (OCT4-pg3) followed that of OCT4A during neural differentiation of the pluripotent
cell line of NTERA-2 (NT2). Although OCT4-pg3 was highly expressed in undifferentiated
NT2 cells, its expression was rapidly down-regulated upon induction of neural differentiation.
Analysis of protein expression of OCT4A, OCT4-pg1, OCT4-pg3, and OCT4-pg4 by
Western blotting indicated that OCT4 pseudogenes cannot produce stable proteins. Consistent
with a newly proposed competitive role of pseudogene microRNA docking sites,
we detected miR-145 binding sites on all transcripts of OCT4 and OCT4 pseudogenes.
Conclusion: Our study suggests a potential coding-independent function for OCT4
pseudogenes during differentiation or tumorigenesis
The risk of chronic kidney disease in relation to anthropometric measures of obesity : A Swedish cohort study
Background: It has been shown that individuals with obesity have a higher risk for chronic kidney disease (CKD). However, it is unclear which measure of obesity is most useful for prediction of CKD in the general population. The aim of this large prospective study was to explore the association between several anthropometric measures of obesity, i. e., body mass index (BMI), waist circumference (WC), waist circumference to height ratio (WHtR), waist-to-hip ratio (WHR), percentage of body fat (BF%), weight, height and incidence of hospitalizations due to CKD, in a population-based cohort study. Methods: The ‘Malmö Diet and Cancer Study (MDCS)’ cohort in Sweden was examined during 1991 to 1996. A total of 28,449 subjects underwent measurement of anthropometric measures and blood pressure and filled out a questionnaire. Incidence of in- and outpatient hospital visits for CKD was monitored from the baseline examination over a mean follow-up of 18 years. Cox proportional hazards regression was used to explore the association between anthropometric measures and incidence of CKD, with adjustments for risk factors. Results: The final study population included 26,723 subjects, 45-73 years old at baseline. Higher values of BMI, WC, WHR, WHtR and weight were associated with an increased risk of developing CKD in both men and women. Only in women, higher values of BF% was associated with higher risk of CKD. Comparing the 4th vs 1st quartile of the obesity measure, the highest hazard ratio (HR) for CKD in men was observed for BMI, HR 1.51 (95% CI: 1.18-1.94) and weight (HR 1.52 (95% CI: 1.19-1.94). For women the highest HR for CKD was observed for BF%, HR 2.01 (95% CI: 1.45-2.78). Conclusions: In this large prospective study, all anthropometric measures of obesity were associated with a substantially increased incidence of CKD, except for BF% in men. Some measures were slightly more predictive for the risk of CKD than others such as BMI and weight in men and BF% in women. In clinical daily practice use of all anthropometric measures of obesity might be equally useful to assess the risk of developing CKD. This study supports the strong evidence for an association between obesity and CKD
Mutation Screening of Six Exons of ABCA4 in Iranian Stargardt Disease Patients
Purpose: Stargardt disease type 1 (STGD1) is a recessively inherited retinal disorder that can cause severe visual impairment. ABCA4 mutations are the usual cause of STGD1. ABCA4 codes a transporter protein exclusively expressed in retinal photoreceptor cells. The gene contains 50 exons. Mutations are most frequent in exons 3, 6, 12, and 13, and exons 10 and 42 each contain two common variations. We aimed to screen these exons for mutations in Iranian STGD1 patients.
Methods: Eighteen STGD1 patients were recruited for genetic analysis. Diagnosis by retina specialists was based on standard criteria, including accumulation of lipofuscin. The six ABCA4 exons were PCR amplified and sequenced by the Sanger method.
Results: One or more ABCA4-mutated alleles were identified in 5 of the 18 patients (27.8%). Five different mutations including two splice site (c.1356+1G>A and c.5836-2A>G) and three missense mutations (p.Gly1961Glu, p.Gly1961Arg, and p.Gly550Arg) were found. The p.Gly1961Glu mutation was the only mutation observed in two patients.
Conclusion: As ABCA4 mutations in exons 6, 12, 10, and 42 were identified in approximately 25% of the patients studied, these may be appropriate exons for screening projects. As in other populations, STDG1 causative ABCA4 mutations are heterogeneous among Iranian patients, and p.Gly1961Glu may be relatively frequent
Ferroelectric-assisted high-performance triboelectric nanogenerators based on electrospun P(VDF-TrFE) composite nanofibers with barium titanate nanofillers
Triboelectric nanogenerators (TENGs) are flexible, efficient, and cost-effective energy harvesters. Here, we develop high-performance ferroelectric-assisted TENGs using electrospun fibrous surfaces based on P(VDF-TrFE) with dispersed BaTiO3 (BTO) nanofillers in either cubic (CBTO) or tetragonal (TBTO) form. TENGs with three types of tribo-negative surface (pristine P(VDF-TrFE), P(VDF-TrFE)/CBTO and P(VDF-TrFE)/TBTO) in contact with PET were investigated and output increased progressively from pristine (0.75 W/m2) to CBTO (2 W/m2) and to TBTO (2.75 W/m2). Accounting for contact pressure, the max output (Voc = 315 V & Jsc = 6.7 µA/cm2) is significantly higher than for TENGs having spin-coated P(VDF-TrFE)/BTO. It is hypothesized that electrospinning increases dipole alignment due to high applied voltages, but also aids the formation of a highly oriented crystalline β-phase via uniaxial stretching. Essentially, tribo-charge transfer is boosted due to increased surface potential owing to enhanced ferroelectric polarization. P(VDF-TrFE)/TBTO produced higher output than P(VDF-TrFE)/CBTO even though permittivity is nearly identical. Thus, it is shown that BTO fillers boost output, not just by increasing permittivity, but also by enhancing the crystallinity and amount of the β-phase (as TBTO produced a more crystalline β-phase present in greater amounts). Finally, the ferroelectric-assisted TENG was integrated with a flexible graphene electrode-based supercapacitor to produce a self-charging system capable of charging to 1.25 V in just 5 min. These results demonstrate that this technology can be valuable in wearable applications where higher power output, more efficient charging and flexibility are paramount
S100B protein as a screening tool for computed tomography findings after mild traumatic brain injury: systematic review and meta-analysis
To determine whether S100B protein in serum can predict intracranial lesions on computed tomography (CT) scan after mild traumatic brain injury (MTBI).Research design: Systematic review and meta-analysisMethods and procedures: A literature search was conducted using Medline, Embase, Cochrane, Google Scholar, CINAHL, SUMSearch, Bandolier, Trip databases, bibliographies from identified articles and review article references. Eligible articles were defined as observational studies including patients with MTBI who underwent post-traumatic head CT scan and assessing the screening role of S100B protein.Main outcomes and results: There was a significant positive association between S100B protein concentration and positive CT scan (22 studies, SMD = 1.92, 95% CI = 1.29-2.45, I = 100%; p 0.20 μg L.Conclusions: After MTBI, serum S100B protein levels are significantly associated with the presence of intracranial lesions on CT scan. Measuring the protein could be useful in screening high risk MTBI patients and decreasing unnecessary CT examinations
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Genomics facilitates evaluation and monitoring of McCloud River Redband Trout (Oncorhynchus mykiss stonei)
AbstractThe McCloud River Redband Trout (MRRT; Oncorhynchus mykiss stonei) is a unique subspecies of rainbow trout that inhabits the isolated Upper McCloud River of Northern California. A major threat to MRRT is introgressive hybridization with non-native rainbow trout from historical stocking and contemporary unauthorized introductions. To help address this concern, we collected RAD-sequencing data on 308 total individuals from MRRT and other California O. mykiss populations and examined population structure using Principal Component and admixture analyses. Our results are consistent with previous studies; we found that populations of MRRT in Sheepheaven, Swamp, Edson, and Moosehead creeks are nonintrogressed. Additionally, we saw no evidence of introgression in Dry Creek, and suggest further investigation to determine if it can be considered a core MRRT conservation population. Sheepheaven Creek was previously thought to be the sole historical lineage of MRRT, but our analysis identified three: Sheepheaven, Edson, and Dry creeks, all of which should be preserved. Finally, we discovered diagnostic and polymorphic SNP markers for monitoring introgression and genetic diversity in MRRT. Collectively, our results provide a valuable resource for the conservation and management of MRRT
Piezoresponse Force Microscopy for Bioelectromechanics
Electromechanical coupling, including piezoelectricity, ferroelectricity, and flexoelectricity, is present in a wide range of organic materials. Such phenomena have been postulated to have a functional role in biological systems, where e.g. conformational changes in proteins can be electrically activated. Investigating the electromechanical properties of biological materials at the micro to nanoscale is therefore crucial for understanding the possible biofunctionality of piezoelectricity and for exploiting such properties in, e.g. sensing, actuating or energy harvesting applications. This chapter provides an overview of the use of piezoresponse force microscopy in the investigation of biomaterials to further our understanding of bioelectromechanics
Solving optimal control problems of the time-delayed systems by a neural network framework
A numerical method using neural networks for solving time-delayed optimal control problems is studied. The problem is first transformed into one without a time-delayed argument, using a Páde approximation. We try to approximate the solution of the Hamiltonian conditions based on the Pontryagin minimum principle (PMP). For this purpose, we introduce an error function that contains all PMP conditions. We then minimise the error function where weights and biases associated with all neurons are unknown. Substituting the optimal values of the weights and biases in the trial solutions, we obtain the optimal solution of the original problem. Several examples are given to show the efficiency of the method