Nevin Manimala

Biometrics. 2021 Mar 25. doi: 10.1111/biom.13460. Online ahead of print.

ABSTRACT

We develop a Bayesian bivariate spatial model for multivariate regression analysis applicable to studies examining the influence of genetic variation on brain structure. Our model is motivated by an imaging genetics study of the Alzheimer’s Disease Neuroimaging Initiative (ADNI), where the objective is to examine the association between images of volumetric and cortical thickness values summarizing the structure of the brain as measured by magnetic resonance imaging (MRI) and a set of 486 SNPs from 33 Alzheimer’s Disease (AD) candidate genes obtained from 632 subjects. A bivariate spatial process model is developed to accommodate the correlation structures typically seen in structural brain imaging data. First, we allow for spatial correlation on a graph structure in the imaging phenotypes obtained from a neighbourhood matrix for measures on the same hemisphere of the brain. Second, we allow for correlation in the same measures obtained from different hemispheres (left/right) of the brain. We develop a mean-field variational Bayes algorithm and a Gibbs sampling algorithm to fit the model. We also incorporate Bayesian false discovery rate (FDR) procedures to select SNPs. We implement the methodology in a new a release of the R package bgsmtr. We show that the new spatial model demonstrates superior performance over a standard model in our application. Data used in the preparation of this article were obtained from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database (https://adni.loni.usc.edu).

PMID:33765325 | DOI:10.1111/biom.13460

Methods Mol Biol. 2021;2252:331-346. doi: 10.1007/978-1-0716-1150-0_16.

ABSTRACT

Ribosome profiling, or Ribo-seq, provides precise information about the position of actively translating ribosomes. It can be used to identify open reading frames (ORFs) that are translated in a given sample. The RiboTaper pipeline, and the ORFquant R package, leverages the periodic distribution of such ribosomes along the ORF to perform a statistically robust test for translation which is insensitive to aperiodic noise and provides a statistically robust measure of translation. In addition to accounting for complex loci with overlapping ORFs, ORFquant is also able to use Ribo-seq as a tool for distinguishing actively translated transcripts from non-translated ones, within a given gene locus.

PMID:33765284 | DOI:10.1007/978-1-0716-1150-0_16

Methods Mol Biol. 2021;2252:313-329. doi: 10.1007/978-1-0716-1150-0_15.

ABSTRACT

The identification of upstream open reading frames (uORFs) using ribosome profiling data is complicated by several factors such as the noise inherent to the procedure, the substantial increase in potential translation initiation sites (and false positives) when one includes non-canonical start codons, and the paucity of molecularly validated uORFs. Here we present uORF-seqr, a novel machine learning algorithm that uses ribosome profiling data, in conjunction with RNA-seq data, as well as transcript aware genome annotation files to identify statistically significant AUG and near-cognate codon uORFs.

PMID:33765283 | DOI:10.1007/978-1-0716-1150-0_15

Environ Sci Pollut Res Int. 2021 Mar 25. doi: 10.1007/s11356-021-13330-w. Online ahead of print.

ABSTRACT

Two polypropylene HVAC electret filters: a regular filter and an antimicrobial filter containing zinc pyrithione (ZPT), were compared for filtration performance. The study was conducted over 7 months in realistic conditions with semi-urban outdoor air. Several parameters were monitored over the study period: the average temperature was about 20 °C and relative humidity about 60%, the average inlet concentration of cultivable microorganisms was 50 CFU m^-3, the average inlet concentration of particles was 10 μg m^-3, the filter pressure drop increased moderately by about 30 Pa, and the particle collection efficiency of soda fluorescein (median diameter 0.35 μm) decreased in the first half of the study period by about 30% and then stabilized. The microbial concentration on the filters was quantified every 2 months using an innovative methodology based on media coupons in conjunction with microorganism quantification by CFU counting, with 5 culture media favorable to bacteria and/or fungi growth. The microbial concentrations on the filters were between 100 and 2000 CFU cm^-2. The antimicrobial effect of zinc pyrithione was confirmed by the fungi cultivated with DRBC agar: no effects in the level of filter clogging were revealed in the range studied. The high statistical deviation in the results regarding the inhibiting effect of zinc pyrithione on bacteria prevents any conclusion.

PMID:33765264 | DOI:10.1007/s11356-021-13330-w

Insights Imaging. 2021 Mar 25;12(1):41. doi: 10.1186/s13244-021-00984-w.

ABSTRACT

BACKGROUND: The COVID-19 pandemic has impacted education in myriad ways, primarily leading to an abrupt paradigm shift in teaching and learning practices towards distance learning. The study aims to assess the effectiveness of teaching radiology to undergraduate medical students using synchronous distance learning compared to traditional on-campus learning through exploring students’ perceived satisfaction and concerns. Students’ perceptions were correlated with their attendance, grades, and frequency of technical difficulties.

METHODS: The study was designed as an observational study involving fourth-year medical students (2019/2020) from two institutions. The cohort students were exposed to traditional learning, distance learning, or both. Students completed an online self-administered questionnaire concerning their perceptions of distance learning. Students’ attendance, engagement, technical difficulties, and post-clerkship knowledge assessments were analyzed using descriptive and inferential statistics.

RESULTS: A total of 145 participants completed the clerkship using the following strategies: traditional learning (n = 66), both traditional and distance learning (n = 67), and distance learning alone (n = 12). The most important result indicates that the abrupt transition to distance learning was well perceived. Most students preferred distance learning over traditional learning in the radiology clerkship (p = .05). During the synchronous sessions, student attendance was high, reaching to 100%. Technical difficulties were limited (1.9%), and they did not affect learning.

CONCLUSION: Synchronous distance teaching promotes learning, interaction, and enjoyment in undergraduate radiology education, and it can be as effective as traditional on-campus learning. The technical difficulties encountered, although they were limited, can be overcome by recording the synchronous sessions.

PMID:33765254 | DOI:10.1186/s13244-021-00984-w

Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz. 2021 Mar 25. doi: 10.1007/s00103-021-03299-9. Online ahead of print.

ABSTRACT

BACKGROUND: During the German division, two culturally very similar populations were exposed to very disparate socioeconomic conditions, which converged again after 1989. The impact of healthcare and life circumstances on mortality differences can better be estimated when cultural explanations are widely neglectable.

OBJECTIVES: For the first time, we analyse harmonised cause-of-death data explicitly by age. Hereby, we can show which ages or birth cohorts were particularly affected by German division and reunification in their mortality and to which causes of death this is attributable.

MATERIALS AND METHODS: We harmonised the German cause-of-death statistics by applying an internationally standardised harmonisation process to account for differences and breaks in cause-of-death coding practices. We analysed the data using decomposition methods.

RESULTS: During the 1980s, east-west disparities were increasing as progress in the reduction of cardiovascular mortality was much stronger in West Germany, notably at older ages. After 1989, East Germany was able to catch up to the west in many areas. This is especially true for elderly persons and women, while east-west disparities are still visible today, particularly among male adult cohorts (1950-1970) strongly affected by the East German transition crisis.

CONCLUSIONS: The lower life expectancy of the East German population in the late 1980s was primarily caused by a slower pace of the cardiovascular revolution. The remaining present-day disparities are rather an aftermath of the East German transition crisis than direct aftereffects of the division.

PMID:33765247 | DOI:10.1007/s00103-021-03299-9

Skeletal Radiol. 2021 Mar 25. doi: 10.1007/s00256-021-03763-2. Online ahead of print.

ABSTRACT

OBJECTIVE: To investigate factors which affect radiographic diagnosis of Hill-Sachs fractures, and find criteria which improve detection.

MATERIALS AND METHODS: Retrospective search was made for the term “Hill Sachs” within MRI reports in our local PACS system, and cases with post-reduction radiographs were included in the study. Prospective diagnoses and subspecialty MSK training of the interpreting radiologist of record were recorded. Images were then retrospectively reviewed by two observers and statistical analysis was performed.

RESULTS: Our retrospective study included 181 cases, of which 35% had prospective radiographic diagnosis of Hill-Sachs fracture. Retrospective review found that 73% of the radiograph series had at least 1 sign of a Hill-Sachs fracture. The internal rotation view showed a Hill-Sachs lesion in 59% of cases, but did not detect it in 14% of cases, where the lesion was instead visible on axillary, external rotation, and/or scapular Y view. Odds ratio of prospective Hill-Sachs detection on radiographs was 2.68 for musculoskeletal fellowship-trained radiologists versus non-musculoskeletal-trained radiologists.

CONCLUSION: Hill-Sachs fractures are often not recognized on post-reduction radiographs. Diagnosis of Hill-Sachs lesion can be significantly increased if radiologists are aware that the internal rotation view may fail to show the injury, and if all 4 views of a shoulder series are scrutinized.

PMID:33765232 | DOI:10.1007/s00256-021-03763-2

Acta Neurochir (Wien). 2021 Mar 25. doi: 10.1007/s00701-021-04824-0. Online ahead of print.

ABSTRACT

INTRODUCTION: Microvascular decompression (MVD) is the preferred surgical method for hemifacial spasm (HFS). The purpose of this study was to analyze the effectiveness and safety of fully endoscopic MVD for HFS relative to microscopic MVD.

MATERIAL AND METHODS: The retrospective study was conducted on HFS patients who underwent microscopic or fully endoscopic MVD from January 2018 to March 2019. All patients were treated at a single institution and by a single surgeon. Patients were divided into two groups based on the surgical method, and clinical data were then compared between groups.

RESULTS: A total of 116 patients, including 54 cases who received fully endoscopic MVD (E group) and 62 cases who received microscopic MVD (M group), were included in this study. Follow-up efficacy did not differ significantly between groups, with total effective rates of 88.9% in the E group and 90.3% in the M group. When postoperative complications were compared individually, there were no statistically significant differences between the two groups; however, the E group had a higher total incidence of complications than the M group (48.1% vs. 29.0%, P = 0.034).

CONCLUSION: Although both fully endoscopic and microscopic MVD for HFS achieved good efficacy, the former method had a higher total incidence of complications. Based on the results of this study, there is no evidence that a microscope can be replaced by a full endoscope in MVD for HFS.

PMID:33765219 | DOI:10.1007/s00701-021-04824-0

Diabetologia. 2021 Mar 25. doi: 10.1007/s00125-021-05436-0. Online ahead of print.

ABSTRACT

AIMS/HYPOTHESIS: It is unclear whether glucose per se has a causal impact on risk of stroke and whether glucose-lowering drugs reduce this risk. This is important for the choice of treatment for individuals at risk. We tested the hypotheses that high plasma glucose has a causal impact on increased risk of ischaemic stroke, and that glucose-lowering drugs reduce this risk.

METHODS: Using a Mendelian randomisation design, we examined 118,838 individuals from two Copenhagen cohorts, the Copenhagen General Population Study and the Copenhagen City Heart Study, and 440,328 individuals from the MEGASTROKE study. Effects of eight glucose-lowering drugs on risk of stroke were summarised by meta-analyses.

RESULTS: In genetic, causal analyses, a 1 mmol/l higher plasma glucose had a risk ratio of 1.48 (95% CI 1.04, 2.11) for ischaemic stroke in the Copenhagen studies. The corresponding risk ratio from the MEGASTROKE study combined with the Copenhagen studies was 1.74 (1.31, 2.18). In meta-analyses of glucose-lowering drugs, the risk ratio for stroke was 0.85 (0.77, 0.94) for glucagon-like peptide-1 receptor agonists and 0.82 (0.69, 0.98) for thiazolidinediones, while sulfonylureas, dipeptidyl peptidase-4 inhibitors, sodium-glucose cotransporter 2 inhibitors, α-glucosidase inhibitors, meglitinides and metformin individually lacked statistical evidence of an effect on stroke risk.

CONCLUSIONS/INTERPRETATION: Genetically high plasma glucose has a causal impact on increased risk of ischaemic stroke. Treatment with glucose-lowering glucagon-like peptide-1 receptor agonists and thiazolidinediones reduces this risk. These results may guide clinicians in the treatment of individuals at high risk of ischaemic stroke.

PMID:33765180 | DOI:10.1007/s00125-021-05436-0

J Orofac Orthop. 2021 Mar 25. doi: 10.1007/s00056-021-00279-1. Online ahead of print.

ABSTRACT

OBJECTIVES: We sought to determine the amount of three-dimensional (3D) movement of soft tissue landmarks in patients who underwent bimaxillary orthognathic surgery.

MATERIALS AND METHODS: We recruited 28 patients (11 women and 17 men), who had received one-piece Le Fort I osteotomy with maxillary advancement and impaction, and bilateral sagittal split ramus osteotomy for mandibular setback. The 3D images were acquired 1-7 days before surgery and at least 6 months after surgery using stereophotogrammetry. We recorded 50 coordinate measurements and correlated the movements between soft and hard tissues. Paired samples t‑test, independent samples t‑test, and Pearson’s correlation analysis were used for statistical analysis.

RESULTS: Patients’ ages ranged from 17-31 years (mean 20.4 ± 3.0 years). The mean advancement and impaction of the maxilla was 4.7 ± 1.2 and 2.2 ± 1.0 mm, respectively. The mean setback of the mandible was 4.2 ± 1.6 mm. Menton (Me) moved significantly closer to the midsagittal plane, and the bilateral alare (Al) and alar curvature (Ac) moved laterally. In addition, pronasale (Prn), bilateral Al, Ac, subnasale (Sn), subspinale (Ss), labiale superior (Ls), sublabiale (Sl), pogonion (Pog), and Me moved upwards. The bilateral cheek bone (Cbp), Al, Ac, Prn, Sn, Ss, Ls, and stomion (Sto) moved forward. Li, Sl, Pog, and Me moved backward. Interestingly, poor correlation was found between soft tissue landmarks and hard tissue movements.

CONCLUSION: We observed 3D coordinate changes in several soft tissue landmarks in the middle and lower thirds of the face. The results of this study may be useful for estimating postoperative changes in similar patients.

PMID:33765157 | DOI:10.1007/s00056-021-00279-1