Tag: pubmed

Stat Med. 2021 Jun 17. doi: 10.1002/sim.9106. Online ahead of print.

ABSTRACT

Joint mean-covariance modeling of multivariate longitudinal data helps to understand the relative changes among multiple longitudinally measured and correlated outcomes. A key challenge in the analysis of multivariate longitudinal data is the complex covariance structure. This is due to the contemporaneous and cross-temporal associations between multiple longitudinal outcomes. Graphical and data-driven tools that can aid in visualizing the dependence patterns among multiple longitudinal outcomes are not readily available. In this work, we show the role of graphical techniques: profile plots, and multivariate regressograms, in developing mean and covariance models for multivariate longitudinal data. We introduce an R package MLGM (Multivariate Longitudinal Graphical Models) to facilitate visualization and modeling mean and covariance patterns. Through two real studies, microarray data from the T-cell activation study and Mayo Clinic’s primary biliary cirrhosis of the liver study, we show the key features of MLGM. We evaluate the finite sample performance of the proposed mean-covariance estimation approach through simulations.

PMID:34139788 | DOI:10.1002/sim.9106

Gerontology. 2021 Jun 17:1-7. doi: 10.1159/000516627. Online ahead of print.

ABSTRACT

INTRODUCTION: The prevalence of malnutrition among inpatient older adults is as high as 20∼50%. Masticatory performance is known to affect the nutritional status of individuals. However, an objective measurement to reflect the real status of masticatory muscle performance is lacking at the bedside.

METHODS: This pilot study analyzed the masticatory performance using surface electromyography (sEMG) of masticatory muscles that measures both muscle strength and muscle tone at the bedside. The nutritional status was measured using the Mini Nutritional Assessment tool. The handgrip strength was measured using a hand dynamometer. The statistical data were analyzed using SPSS 25 software.

RESULTS: The data revealed that female inpatient older adults more frequently had substandard handgrip strength (p = 0.028), an at-risk and poor nutritional status (p = 0.005), and a higher masseter muscle tone (p = 0.024). Inpatient older adults with an at-risk and poor nutritional status had an older age (p = 0.016), lower handgrip strength (p = 0.001), and higher average masseter muscle tone (p = 0.01). A high masseter muscle tone predicted the risk of having an at-risk and poor nutritional status. The at-risk or poor nutritional status predicted having a substandard handgrip strength by 5-fold.

CONCLUSIONS: A high masticatory muscle tone predicts malnutrition and frailty. Medical professionals should combat masticatory dysfunction-induced malnutrition by detecting masticatory muscle performance using sEMG and referring patients to dental professionals. Additionally, encouraging inpatient older adults to perform oral motor exercise is recommended.

PMID:34139690 | DOI:10.1159/000516627

Blood Purif. 2021 Jun 17:1-8. doi: 10.1159/000515825. Online ahead of print.

ABSTRACT

INTRODUCTION: Liver failure is associated with hepatic and extrahepatic organ failure leading to a high short-term mortality rate. Extracorporeal albumin dialysis (ECAD) aims to reduce albumin-bound toxins accumulated during liver failure. ECAD detoxifies blood using albumin dialysis through an artificial semipermeable membrane with recirculation (molecular adsorbent recirculating system, MARS) or without (single-pass albumin dialysis, SPAD).

METHODS: We performed a randomized crossover open trial in a surgical intensive care unit. The primary outcome of the study was total bilirubin reduction during MARS and during SPAD therapies. The secondary outcomes were conjugated bilirubin and bile acid level reduction during MARS and SPAD sessions and tolerance of dialysis system devices. Inclusion criteria were adult patients presenting liver failure with factor V activity <50% associated with bilirubin ≥250 μmol/L and a complication (either hepatic encephalopathy, severe pruritus, or hepatorenal syndrome). For MARS and SPAD, the dialysis flow rate was equal to 1,000 mL/h.

RESULTS: Twenty crossovers have been performed. Baseline biochemical characteristics (bilirubin, ammonia, bile acids, creatinine, and urea) were not statistically different between MARS and SPAD. Both ECAD have led to a significant reduction in total bilirubin (-83 ± 67 μmol/L after MARS; -122 ± 118 μmol/L after SPAD session), conjugated bilirubin (-82 ± 61 μmol/L after MARS; -105 ± 96 μmol/L after SPAD session), and bile acid levels (-64 ± 75 μmol/L after MARS; -56 ± 56 μmol/L after SPAD session), all nondifferent comparing MARS to SPAD.

CONCLUSION: A simple-to-perform SPAD therapy with equal to MARS dialysate flow parameters provides the same efficacy in bilirubin and bile acid removal. However, clinically relevant endpoints have to be evaluated in randomized trials to compare MARS and SPAD therapies and to define the place of SPAD in the liver failure care program.

PMID:34139706 | DOI:10.1159/000515825

Lifestyle Genom. 2021 Jun 17:1-10. doi: 10.1159/000514338. Online ahead of print.

ABSTRACT

BACKGROUND/AIM: An alarming increase in vitamin D deficiency even in sunny regions highlights the need for a better understanding of the genetic background of the vitamin D endocrine system and the molecular mechanisms of gene polymorphisms of the vitamin D receptor (VDR). In this study, the serum levels of 25(OH)D3 were correlated with common VDR polymorphisms (ApaI, BsmI, FokI, and TaqI) in 98 subjects of a Greek homogeneous rural population.

METHODS: 25(OH)D3 concentration was measured by ultra-HPLC, and the VDR gene polymorphisms were identified by quantitative real-time PCR followed by amplicon high-resolution melting analysis.

RESULTS: Subjects carrying either the B BsmI (OR: 0.52, 95% CI: 0.27-0.99) or t TaqI (OR: 2.06, 95%: 1.06-3.99) allele presented twice the risk for developing vitamin D deficiency compared to the reference allele. Moreover, subjects carrying 1, 2, or all 3 of these genotypes (BB/Bb, Tt/tt, and FF) demonstrated 2-fold (OR: 2.04, 95% CI: 0.42-9.92), 3.6-fold (OR: 3.62, 95% CI: 1.07-12.2), and 7-fold (OR: 6.92, 95% CI: 1.68-28.5) increased risk for low 25(OH)D3 levels, respectively.

CONCLUSIONS: Our findings reveal a cumulative effect of specific VDR gene polymorphisms that may regulate vitamin D concentrations explaining, in part, the paradox of vitamin D deficiency in sunny regions, with important implications for precision medicine.

PMID:34139712 | DOI:10.1159/000514338

J Phys Condens Matter. 2021 Jun 17. doi: 10.1088/1361-648X/ac0c3c. Online ahead of print.

ABSTRACT

We present a comprehensive study of the linear response of interacting underdamped Brownian particles to simple shear flow. We collect six different routes for computing the response, two of which are based on the symmetry of the considered system and observable with respect to the shear axes. We include the extension of the Green-Kubo relation to underdamped cases, which shows two unexpected additional terms. These six computational methods are applied to investigate the relaxation of the response towards the steady state for different observables, where interesting effects due to interactions and a finite particle mass are observed. Moreover, we compare the different response relations in terms of their statistical efficiency, identifying their relative demand on experimental measurement time or computational resources in computer simulations. Finally, several measures of breakdown of linear response theory for larger shear rates are discussed.

PMID:34139676 | DOI:10.1088/1361-648X/ac0c3c

Cerebrovasc Dis. 2021 Jun 17:1-7. doi: 10.1159/000515707. Online ahead of print.

ABSTRACT

BACKGROUND: Acute infarction patterns have been described in cardioembolic stroke, mainly with atrial fibrillation (AF) or patent foramen ovale. We aimed to analyse acute infarction magnetic resonance imaging (MRI) characteristics in stroke patients with intracardiac thrombus (ICT) compared with stroke patients with AF.

METHODS: We performed a retrospective study analysing brain MRI scans of consecutive acute symptomatic cardioembolic infarction patients associated with ICT or AF who were recruited and registered in the stroke database between June 2018 and November 2019. Diffusion-weighted imaging performed within 1 week after symptom onset, intra-/extracranial vessel imaging, echocardiography, and ≥24-h ECG monitoring were required for inclusion. Baseline, biological, and echocardiography characteristics were assessed. Analysed MRI characteristics were infarction location (anterior/middle/posterior cerebral artery territory; anterior/posterior/mixed anterior-posterior circulation; multiterritorial infarction; brainstem; cerebellum; small cortical cerebellar infarctions [SCCIs] or non-SCCI; cortical/subcortical/cortico-subcortical), lesion number, subcortical lesion size (> or <15 mm), and total infarction volume.

RESULTS: We included 28 ICT and 94 AF patients presenting with acute stroke. ICT patients were younger (median age 66 vs. 81 years, p < 0.001), more frequently male (79 vs. 47%, p = 0.003), and smokers (39 vs. 17%, p = 0.013), had more frequent history of diabetes (36 vs. 18%, p = 0.049) and ischaemic heart disease (57 vs. 21%, p < 0.001), and had lower HDL cholesterol levels (0.39 vs. 0.53 g/L, p < 0.001). On MRI, SCCI was more frequent in the ICT group (25 vs. 5%, p = 0.006) in the absence of other differences in infarction localisation, number, size, or volume on MRI. On multivariate analysis, younger age (p < 0.001), history of ischaemic heart disease (p < 0.001), and low HDL cholesterol levels (p = 0.01) were significantly associated with ICT. Results approaching statistical significance were observed for SCCI (more frequent in the ICT group, p = 0.053) and non-SCCI (more frequent in the AF group, p = 0.053) on MRI.

CONCLUSIONS: ICT-related stroke is associated with acute SCCI presence on MRI. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT04456309.

PMID:34139688 | DOI:10.1159/000515707

Int J Hyg Environ Health. 2021 Jun 14;236:113790. doi: 10.1016/j.ijheh.2021.113790. Online ahead of print.

ABSTRACT

BACKGROUND: Ankle-brachial index (ABI) and cardio-ankle vascular index (CAVI) are surrogate measures of atherosclerosis based on the functional performance of vessels, and are highly related to cardiovascular events. However, only a few longitudinal studies have been conducted on their associations with long-term air pollution exposure.

OBJECTIVE: This study aimed to examine whether long-term air pollution exposure is associated with ABI and CAVI in workers of the Electricity Generating Authority of Thailand (EGAT) in the Bangkok Metropolitan Region (BMR).

METHODS: This longitudinal study included 1261 participants (age range, 57-76 years as of 2007) of the EGAT study (2007-2017). ABI and CAVI were measured in 2007, 2012, and 2017. Annual mean concentrations of particulate matter ≤10 μm in diameter (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), ozone (O₃), and carbon monoxide (CO) were estimated by ordinary kriging using data from 22 background and 7 traffic monitoring stations in BMR between 2002 and 2017. Linear mixed-effects models were used to assess associations between air pollution (expressed as 1-year, 3-year, and 5-year average concentration) and ABI and CAVI (expressed as percent changes per interquartile range (IQR) increase in PM₁₀, O₃, NO₂, SO_2, and CO). We also applied the mixed-effect ordinal logistic models to calculate odds ratios (ORs) of having high or moderate CAVI per an IQR increase in air pollution.

RESULTS: After controlling for potential confounders, 1-year average CO was negatively associated with ABI, but not significantly (-0.48%, 95% CI: -1.03, 0.07). Three-year average NO₂ was positively associated with CAVI (6.67%, 95% CI: 0.21, 13.1). In contrast, 1-year average PM₁₀ was inversely associated with CAVI although the association was not significant. Although not significantly, 1-year average NO₂ and CO were positively associated with prevalence of high or moderate CAVI.

CONCLUSIONS: Although not statistically significant, long-term NO₂ and CO exposure was associated with ABI and CAVI in the participants of the EGAT study.

PMID:34139634 | DOI:10.1016/j.ijheh.2021.113790

Dev Cogn Neurosci. 2021 Jun 11;50:100975. doi: 10.1016/j.dcn.2021.100975. Online ahead of print.

ABSTRACT

In order to become proficient native speakers, children have to learn the morpho-syntactic relations between distant elements in a sentence, so-called non-adjacent dependencies (NADs). Previous research suggests that NAD learning in children comprises different developmental stages, where until 2 years of age children are able to learn NADs associatively under passive listening conditions, while starting around the age of 3-4 years children fail to learn NADs during passive listening. To test whether the transition between these developmental stages occurs gradually, we tested children’s NAD learning in a foreign language using event-related potentials (ERPs). We found ERP evidence of NAD learning across the ages of 1, 2 and 3 years. The amplitude of the ERP effect indexing NAD learning, however, decreased with age. These findings might indicate a gradual transition in children’s ability to learn NADs associatively. Cognitively, this transition might be driven by children’s increasing knowledge of their native language, hindering NAD learning in novel contexts. Neuroanatomically, maturation of the prefrontal cortex might play a crucial role, promoting top-down learning, affecting bottom-up, associative learning. In sum, our study suggests that NAD learning under passive listening conditions undergoes a gradual transition between different developmental stages during early childhood.

PMID:34139635 | DOI:10.1016/j.dcn.2021.100975

J Environ Manage. 2021 Jun 14;294:113021. doi: 10.1016/j.jenvman.2021.113021. Online ahead of print.

ABSTRACT

Denitrification is a significant regulator of nitrogen pollution in diverse landscapes but is difficult to quantify. We examined relationships between denitrification potential and soil and landscape properties to develop a model that predicts denitrification potential at a landscape level. Denitrification potential, ancillary soil variables, and physical landscape attributes were measured at study sites within urban, suburban, and forested environments in the Gwynns Falls watershed in Baltimore, Maryland in a series of studies between 1998 and 2014. Data from these studies were used to develop a statistical model for denitrification potential using a subset of the samples (N = 188). The remaining measurements (N = 150) were used to validate the model. Soil moisture, soil respiration, and total soil nitrogen were the best predictors of denitrification potential (R²_adj = 0.35), and the model was validated by regressing observed vs. predicted values. Our results suggest that soil denitrification potential can be modeled successfully using these three parameters, and that this model performs well across a variety of natural and developed land uses. This model provides a framework for predicting nitrogen dynamics in varying land use contexts. We also outline approaches to develop appropriate landscape-scale proxies for the key model inputs, including soil moisture, respiration, and soil nitrogen.

PMID:34139648 | DOI:10.1016/j.jenvman.2021.113021

Public Health. 2021 Jun 14;196:29-34. doi: 10.1016/j.puhe.2021.04.030. Online ahead of print.

ABSTRACT

OBJECTIVES: Little is known about the impact of the 2008 global economic recession on childhood obesity in Portugal. Thus, this study’s goals were to compare weight status of children during and after the economic crisis according to their neighbourhood environment features and to assess changes in specific dietary habits during the economic crisis.

STUDY DESIGN: Cross-sectional study.

METHODS: Data including weight, height, residence address to allow its geocoding and dietary habits changes during the crisis from children living in Lisbon municipality were collected in 2009 (N = 929) and in 2016 (N = 1751). A multidimensional environment index, with data of both built and socioeconomic nature collected at the statistical section level (areas comprised 300 dwellers) in the 2011 census, was used to characterize neighbourhoods.

RESULTS: Overall, the proportion of children who are overweight or obese living in the socioeconomically vulnerable areas decreased in 2016. Families living in the latter areas stopped buying some food items, started to buy cheaper food items, cooked more meals at home and ate less in restaurants. In 2016, the risk for overweight and obesity increased in children who lived in the least advantageous areas. Living in areas with high socioeconomic status or most advantageous areas no longer represented a decreased risk of being overweight or obese in children in 2016 as it did in 2009.

CONCLUSIONS: This study suggests that the economic crisis enhanced the social inequalities regarding childhood obesity. These results aid the development of evidence-based strategies to lessen the social inequities in health outcomes created by the crisis.

PMID:34139606 | DOI:10.1016/j.puhe.2021.04.030