Tag: pubmed

Med Image Anal. 2021 Sep 30;75:102252. doi: 10.1016/j.media.2021.102252. Online ahead of print.

ABSTRACT

Evidence of the non stationary behavior of functional connectivity (FC) networks has been observed in task based functional magnetic resonance imaging (fMRI) experiments and even prominently in resting state fMRI data. This has led to the development of several new statistical methods for estimating this time-varying connectivity, with the majority of the methods utilizing a sliding window approach. While computationally feasible, the sliding window approach has several limitations. In this paper, we circumvent the sliding window, by introducing a statistical method that finds change-points in FC networks where the number and location of change-points are unknown a priori. The new method, called cross-covariance isolate detect (CCID), detects multiple change-points in the second-order (cross-covariance or network) structure of multivariate, possibly high-dimensional time series. CCID allows for change-point detection in the presence of frequent changes of possibly small magnitudes, can assign change-points to one or multiple brain regions, and is computationally fast. In addition, CCID is particularly suited to task based data, where the subject alternates between task and rest, as it firstly attempts isolation of each of the change-points within subintervals, and secondly their detection therein. Furthermore, we also propose a new information criterion for CCID to identify the change-points. We apply CCID to several simulated data sets and to task based and resting state fMRI data and compare it to recent change-point methods. CCID may also be applicable to electroencephalography (EEG), magentoencephalography (MEG) and electrocorticography (ECoG) data. Similar to other biological networks, understanding the complex network organization and functional dynamics of the brain can lead to profound clinical implications. Finally, the R package ccid implementing the method from the paper is available from CRAN.

PMID:34700242 | DOI:10.1016/j.media.2021.102252

Clin Biomech (Bristol, Avon). 2021 Oct 7;90:105508. doi: 10.1016/j.clinbiomech.2021.105508. Online ahead of print.

ABSTRACT

BACKGROUND: The purpose of this study is to compare compression generated by a Precice magnetic lengthening intramedullary nail and a 5.0 mm limited contact dynamic compression plate.

METHODS: Transverse osteotomy sites were created in the femoral shaft of ten Sawbones fourth generation composite femurs. Antegrade 10-degree trochanteric Precice nails and 8-hole, 5.0 mm plates were used for fixation. The plates were compressed by placing a neutral screw and three eccentrically drilled compression screws on alternating sides of the osteotomy. Average compression and distribution of compression were compared, and P-values <0.05 were considered statistically significant.

FINDINGS: The Precice nail generated an average of 2.38 megapascal across the osteotomy sites. The plate generated an average of 0.70 megapascal (P < 0.001) with the initial compression screw, 0.93 megapascal (P < 0.001) after the second screw, and 1.04 megapascal (p < 0.001) after the final screw. The distribution of compression was assessed utilizing a polar transformation to compare pressure values. We found that the distribution of compression was more circumferentially uniform in the Precice nail group (P = 0.046).

INTERPRETATION: This study demonstrates that an electromagnetic intramedullary device is capable of generating significantly higher compression, in a more uniform distribution, than a 5.0 mm limited contact dynamic compression plate in a Sawbones model. The results indicate that electromagnetic intramedullary nail systems may be an ideal alternative to compression plating for treatment of at-risk fractures, nonunions, delayed unions, and intercalary allograft reconstruction.

PMID:34700236 | DOI:10.1016/j.clinbiomech.2021.105508

Biomed Pharmacother. 2021 Oct 23;144:112347. doi: 10.1016/j.biopha.2021.112347. Online ahead of print.

ABSTRACT

New therapeutic targets are revolutionizing colorectal cancer clinical management, opening new horizons in metastatic patients’ outcome. Polo Like Kinase1 (PLK1) inhibitors have high potential as antitumoral agents, however, the emergence of drug resistance is a major challenge for their use in clinical practice. Overcoming this challenge represents a hot topic in current drug discovery research. BI2536-resistant colorectal cancer cell lines HT29_R, RKO_R, SW837_R and HCT116_R, were generated in vitro and validated by IG₅₀ assays and xenografts models by the T/C ratio. Exons 1 and 2 of PLK1 gene were sequenced by Sanger method. AXL pathway, Epithelial-to-Mesenchymal transition (EMT) and Multidrug Resistance (MDR1) were studied by qPCR and western blot in resistant cells. Simvastatin as a re-sensitizer drug was tested in vitro and the drug combination strategies were validated in vitro and in vivo. PLK1 gene mutation R136G was found for RKO_R. AXL pathway trough TWIST1 transcription factor was identified as one of the mechanisms involved in HT29_R, SW837_R and HCT116_R lines, inducing EMT and upregulation of MDR1. Simvastatin was able to impair the mechanisms activated by adaptive resistance and its combination with BI2536 re-sensitized resistant cells in vitro and in vivo. Targeting the mevalonate pathway contributes to re-sensitizing BI2536-resistant cells in vitro and in vivo, raising as a new strategy for the clinical management of PLK1 inhibitors.

PMID:34700228 | DOI:10.1016/j.biopha.2021.112347

Dev Cogn Neurosci. 2021 Oct 16;52:101021. doi: 10.1016/j.dcn.2021.101021. Online ahead of print.

ABSTRACT

Advances in our understanding of risk and resilience factors in adolescent brain health and development increasingly demand a broad set of assessment tools that consider a youth’s peer, family, school, neighborhood, and cultural contexts in addition to neurobiological, genetic, and biomedical information. The Culture and Environment (CE) Workgroup (WG) of the Adolescent Brain Cognitive Development (ABCD) Study curates these important components of the protocol throughout ten years of planned data collection. In this report, the CE WG presents an update on the evolution of the ABCD Study® CE protocol since study inception (Zucker et al., 2018), as well as emerging findings that include CE measures. Background and measurement characteristics of instruments present in the study since baseline have already been described in our 2018 report, and therefore are only briefly described here. New measures introduced since baseline are described in more detail. Descriptive statistics on all measures are presented based on a total sample of 11,000+ youth and their caregivers assessed at baseline and the following two years. Psychometric properties of the measures, including longitudinal aspects of the data, are reported, along with considerations for future measurement waves. The CE WG ABCD® components are an essential part of the overall protocol that permits characterization of the unique cultural and social environment within which each developing brain is transactionally embedded.

PMID:34700197 | DOI:10.1016/j.dcn.2021.101021

Arch Gerontol Geriatr. 2021 Oct 3;98:104545. doi: 10.1016/j.archger.2021.104545. Online ahead of print.

ABSTRACT

OBJECTIVES: This study aimed to explore the gender and residence (rural/urban) differences in the associations between the specific dimensions of social support and subjective well-being (SWB) among the Chinese oldest-old.

METHODS: This study included 12,989 individuals aged ≥ 80 from 2011, 2014, and 2018 waves of the Chinese Longitudinal Healthy Longevity Survey. SWB was measured by ten items covering self-rated life satisfaction, positive emotions (optimism, happiness, personal control, and conscientiousness), and negative emotions (loneliness, anxiety, uselessness, depression, and boring feelings). Social support included the variables of marriage quality, living arrangements, contacts with others, children’s and siblings’ frequent visits and telecommunications, children and siblings living nearby, the main source of financial support, adequate financial support, social security and commercialized insurances, community social services, the caregiver when sick, and main medical expenses payer. Generalized estimating equation models were used to determine the effects of social support on the SWB.

RESULTS: Gender differences were found in the associations of living arrangements, contacts with others, children’s frequent visits and telecommunications, community social services, caregiver when sick, and main medical expenses payer with SWB. Residence differences were found in the associations of living arrangements, contacts with others, children’s frequent visits and telecommunications, siblings’ frequent visits, community social services, and main medical expenses payer with SWB.

CONCLUSIONS: There are gender and residence differences in the relationships between many dimensions of social support and SWB. Gender and residence-tailored interventions for social support are necessary to promote the well-being of the oldest old.

PMID:34700136 | DOI:10.1016/j.archger.2021.104545

Mar Pollut Bull. 2021 Oct 23;173(Pt B):113072. doi: 10.1016/j.marpolbul.2021.113072. Online ahead of print.

ABSTRACT

Sediment core samples from high tide lines and in submerged zones as well as surface water samples from eight beaches of Tenerife were analysed. Sampling was conducted over a period of one year in intervals of 5 weeks. The majority of particles were found in the high tide sediment (66%), followed by water samples (23%) and finally in sediment from submerged zones (11%). Regarding the particle amount per volume (items/L), accumulation in sediment samples was statistically higher compared to water samples. Mean values of items/L were higher in high tide sediments. In high tide and water samples, mostly white and transparent particles >1 mm were found. More than 70% were represented by fragments. In sediments from submerged zones, yellow and blue microparticles (<1 mm) were predominant and 61.9% consisted of fibres. Larger particles were mainly identified as PP, PE, PS, PTFE and PVC, while polymer types of smaller particles were more variable.

PMID:34700151 | DOI:10.1016/j.marpolbul.2021.113072

Theriogenology. 2021 Oct 20;177:151-156. doi: 10.1016/j.theriogenology.2021.10.012. Online ahead of print.

ABSTRACT

There are controversial reports on the restoration of eroded telomere length in offspring produced by somatic cell nuclear transfer (SCNT) in different animal species. To the best of our knowledge, no earlier studies report the telomere length in naturally produced or cloned animals in any of the camelid species. Therefore, the present study was conducted to estimate the telomere length in dromedary camels produced by SCNT, the donor cells, and their age-matched naturally produced counterparts by Terminal Restriction Fragment (TRF) length analysis and real-time Q PCR T/S ratio methods. Genomic DNA was extracted from venous blood collected from 6 cloned animals and their age-matched counterparts. Using the southern blot technique, digested DNA was blotted onto a positively charged nylon membrane, and its hybridization was carried out using telomere (TTAGGG)n specific, DIG-labeled hybridization probe (Roche Diagnostics, Germany) at 42 °C for 4 h. Stringent washes were carried out at the same temperature, followed by a chemiluminescence reaction. The signals were captured using the Azure Biosystems C600 gel documentation system. A TeloTool program from MATLAB software with a built-in probe intensity correction algorithm was used for TRF analysis. The experiment was replicated three times, and the data, presented as mean ± SEM, were analyzed using a two-sample t-test (MINITAB statistical software, Minitab ltd, CV3 2 TE, UK). No difference was found in the mean telomere length of cloned camels when compared to their naturally produced age-matched counterparts. However, the telomere length was more (P < 0.05) than that of the somatic cells used for producing the SCNT embryos. A moderate positive Pearson correlation coefficient (r = 0.6446) was observed between the telomere lengths estimated by TRF and Q PCR T/S ratio method. In conclusion, this is the first study wherein we are reporting telomere length in naturally produced and cloned dromedary camels produced by somatic cell nuclear transfer. We found that telomere lengths in cloned camels were similar to their age-matched naturally produced counterparts, suggesting that the camel cytoplast reprograms the somatic cell nucleus and restores the telomere length to its totipotency stage.

PMID:34700072 | DOI:10.1016/j.theriogenology.2021.10.012

Eur J Radiol. 2021 Oct 13;144:109999. doi: 10.1016/j.ejrad.2021.109999. Online ahead of print.

ABSTRACT

PURPOSE: MRI is the imaging modality of choice for soft tissue-related spine disease. However, CT is superior to MRI in providing clear visualization of bony morphology. The purpose of this study is to test equivalency of MRI-based synthetic CT to conventional CT in quantitatively assessing bony morphology of the lumbar spine.

METHOD: A prospective study with an equivalency design was performed. Adult patients who had undergone MRI and CT of the lumbar spine were included. Synthetic CT images were generated from MRI using a deep learning-based image synthesis method. Two readers independently measured pedicle width, spinal canal width, neuroforamen length, anterior and posterior vertebral body height, superior and inferior vertebral body length, superior and inferior vertebral body width, maximal disc height, lumbar curvature and spinous process length on synthetic CT and CT. The agreement among CT and synthetic CT was evaluated using equivalency statistical testing.

RESULTS: Thirty participants were included (14 men and 16 women, range 20-60 years). The measurements performed on synthetic CT of pedicle width, spinal canal width, vertebral body height, vertebral body width, vertebral body length and spinous process length were statistically equivalent to CT measurements at the considered margins. Excellent inter- and intra-reader reliability was found for both synthetic CT and CT.

CONCLUSIONS: Equivalency of MRI-based synthetic CT to CT was demonstrated on geometrical measurements in the lumbar spine. In combination with the soft tissue information of the conventional MRI, this provides new possibilities in diagnosis and surgical planning without ionizing radiation.

PMID:34700094 | DOI:10.1016/j.ejrad.2021.109999

Am J Obstet Gynecol MFM. 2021 Oct 23:100521. doi: 10.1016/j.ajogmf.2021.100521. Online ahead of print.

ABSTRACT

Infertility treatments have benefited millions of couples to have their own children, but resultant multiple pregnancies with their increased morbidity and mortality have been a significant complication. Fetal reduction (FR) was developed to ameliorate those. Over 30 years of publications show that FR has been highly successful in substantially reducing both mortality and morbidity. As with most radically new techniques, initial cases were in the “nothing to lose” category. With experience, indications liberalize, and quality of life issues increase as a proportion of cases. Overall risks for twins are not twice singletons; they are about 4 – 5 x higher. In experienced hands, the combination of genetic testing by CVS followed by FR has made most multiples behave statistically as if they were originally the lower number. Use of microarray analysis to better determine fetal genetic health before deciding on which fetus(es) to keep or reduce further improves pediatric outcomes. With increasing experience and lower average starting numbers, the proportion of FRs to a singleton has increased considerably. Twins to a singleton FR now constitute an increasing proportion of cases performed. Data on such cases show improved outcomes, and we believe FR should be at least discussed and offered to all patients with a dichorionic twin pregnancy or higher. With increasing reliance upon elective single embryo transfer (eSET), monochorionic twins have substantially increased which have much higher complication rates than dichorionic twins. Furthermore, monochorionic twins cannot be readily, safely reduced so the adverse perinatal statistics of eSET are a major set-back for good outcomes. While eSET is appropriate for some, we believe that for many couples, transfer of 2 embryos is generally a more rational approach.

PMID:34700026 | DOI:10.1016/j.ajogmf.2021.100521

Food Chem. 2021 Oct 20;373(Pt A):131431. doi: 10.1016/j.foodchem.2021.131431. Online ahead of print.

ABSTRACT

Previous researches have been conducted evaluating the volatile compounds of pork. However, data regarding the changes in volatiles and metabolic pathways during pork storage were inadequately investigated. Herein, a headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC/MS) coupled multivariate analysis was proposed for characterizing the profiles of volatile compounds and metabolic pathways during pork storage. A total of 37 metabolites, including aldehydes, ketones, alcohols etc. were successfully identified. Multivariate statistical analysis revealed a substantial variation in metabolite phenotype among samples over the pork storage period, with 12 characteristic metabolites and 5 potential characteristic metabolites screened as biomarkers. Moreover, three metabolomic pathways analysis and transformation between each other (thermal reactions, lipid metabolism and amino acid metabolism) reveals the underlying mechanisms of metabolites change of pork. Therefore, the present study may provide insight into future understanding of the variation in the pork metabolite profiles.

PMID:34700034 | DOI:10.1016/j.foodchem.2021.131431